It sounds like you're pretty torn on what you need vs what you want - and the pressure is always to go with the tool that will give you the most room to grow. But sometimes, you do have to seriously weigh how much you actually intend to grow, and how much the shortcomings of a particular system will actually affect you. Having read through this whole thread and all of the recommendations, the common theme (no surprise as we are camera enthusiasts!) is that going with a DSLR is basically the only reasonable choice. Whether you go with Canon or Nikon, as 75% of all people do whether for genuine reasons like preferred ergonomics or features, or forced reasons like peer pressure or brand snobbery...or one of the alternative smaller brands like Olympus (or the not-yet-mentioned Pentax & Sony)...you can't really go wrong, and will end up with a camera that will easily be capable of shooting all of the photo examples you posted. Whether one is slightly better than another when viewing a 50-pixel-wide segment of the photo at 200% and looking for blemishes the size of an ant...well, that just doesn't really matter for 99% of most people's needs - they're all good, so don't worry so much about that.
Now, here's where I go off the grid (you know I'm already a renegade on these boards, since my DSLR is a Sony...the only one on tmip!). I truly think that a very good P&S camera would be the perfect camera choice for most budding photographers who don't have high skill levels and are looking to learn. In fact, I think alot of people who bought DSLRs would have been better served with a high-end P&S camera...though they'd never admit it. And there are photos out there taken with high-end P&S cameras that win photo contests, are sold for profit at art shows, and even get published in major magazines. Here's the thing: a good P&S has alot of traits that an entry-level DSLR doesn't have without spending thousands of dollars for lenses. I know because until 6 months ago, I shot with a P&S camera for several years, learned quite literally everything I know about photography with it, and even made a profit from my photos enough to BUY my DSLR and lenses. I started with digital photography as a noob - I didn't know what an aperture was or what ISO was. My camera for the last 2 1/2 years before my DSLR was a Sony H5, an ultra-zoom camera. I think this category of camera is marvelous - the perfect learning tool and all-round flexible camera. Brand doesn't much matter - Canon, Sony, Nikon, Fuji, Casio, Panasonic - all have very nice ultra-zooms. First off, look at the controls - you've got full auto, Program mode, Shutter and aperture priority, and manual modes. So you've got room to grow as you learn how to control the camera. They come with viewfinders...but they're electronic - which does allow you to see the actual changes on screen as you adjust the aperture, shutter speed, ISO, white balance, etc - so you see when you've got the settings right, and understand how each change in settings affects your shot. Or you can use the bigger LCD. Most of them have a lens range equivalent to anywhere from 28mm to over 500mm...yet can fit in the palm of your hand and weigh 1/4 what an entry-level DSLR body alone does. To get that range in a DSLR, you're spending well over $2,000...no matter what brand you buy. Most of them have a maximum aperture of F2.8 as the baseline...and no more than 4.5 or so at full tele. Most cheaper DSLR lenses start at F3.5-4.5...and anything with 300mm or more is going to be much less sensitive, like F6.5 or so. Unless, of course, you want to whip out the serious debit cards and spend high-4-figures for an F2.8 300mm lens. In good light, the best ultra-zooms have nearly identical focus speeds, shutter delays, and half-press/full-press delay as entry level DSLRs...they can be slower in low light, but not much...and still manage to achieve focus. They are a little slower in continuous shooting modes.
So, an ultrazoom can give you a moderately wide to ultra-telephoto lens, with good sensitivity of F2.8-3.7, in a superlight and small package...and the whole thing will usually cost under $500...often much less. And other than pixel-peeping obsessed folks blowing photos up to sizes far beyond what anyone will ever view or print a photo at, noone would be able to tell the difference in the quality of daylight shots or slow shutter shots at lower ISOs. Unless you need to print 4-foot by 5-foot photos! And while a DSLR does indeed shoot more cleanly at high ISOs, and perform better overall in low light focusing...what percentage of your photos are going to be high-ISO shots? Do you shoot a ton of action sports in dim stadiums that require high shutter speeds, or like to do hand-held nighttime snapshots? OK, then high ISO performance will be very important. If you're just a person looking to take nice vacation photos, some nice hobby photos like wildlife or landscapes, and want room to grow and expand your knowledge with photography to discover if it is something you want to pursue beyond what the normal folks do - where it becomes 'enthusiasm' and you're truly hooked on photography like the rest of us here...then a good ultra-zoom P&S will give you years of great shots, plenty of room to grow as a photographer, and if you find yourself someday bumping into the limitations of the camera, then that means you've become a pretty good photographer and have become a true enthusiast...and you can start hunting for the DSLR system you want the most.
That's what I did. After lots of fun, lots of learning, lots of success, and a little side business with my ultra-zoom, I finally after almost 3 years found myself wanting to push into the very few areas where the P&S couldn't go - and I was willing to spend money to get there. I wanted to pursue wildlife photography more avidly, which would require better continuous shooting modes and quick focusing for shooting animals and birds in motion. I wanted to play with hand-held candids and night shots at high ISO. I wanted to expand my lens range to super-wide, and big-time tele. It was time for me to make the move...and I was willing to accept the compromises - more weight, more bulk, and lots of money.
Feel free to browse my galleries - a majority of the shots were taken with my H5...everything from night shots to action shots to wildlife to landscapes to Disney. Shots taken since June are mostly with the DSLR. I don't feel like my H5 shots are really any different or worse than what I can do with the DSLR - I can just now shoot more types of shots. In other words, I can do the same things just as well as before, and a few things better:
http://www.pbase.com/zackiedawg
As for the points that have been mentioned on picking a DSLR system - I went with Sony for several reasons mentioned above on the Olympus. 1. I wanted in-body stabilization, as it allows the purchase of cheaper lenses that don't have to have built-in stabilization, and moreover, gives you stabilization on all of your lenses - even the ones that don't have stabilization available in-lens with the other brands (like wide lenses, low light primes, etc). 2. I liked their live view system - it is very easy to switch back and forth from, and is the only one that suffers no slowdowns in performance or focus speed when in use. 3. I liked the cheap backlog of available Minolta lenses that will work with the camera - all autofocus, and all stabilized. 4. I liked the camera's ergonomics - it feels good in my hand and has all the bells and whistles I like. 5. The price was right, and I've had great experience with the brand in other cameras. I wouldn't have hesitated to go with Canon, Nikon, Olympus, or Pentax...I don't honestly believe any entry-level camera is significantly better than another. Each may have a feature here, or a slight advantage there, but taking everything into consideration, they're all just fine.
There! That's my contribution to the thread. Right now, Tim is thinking 'Ah ha! I knew he'd come in with his P&S spiel!' And most of the Canon and Nikon guys are rolling their collective eyes and sighing.
Yep...even as a DSLR user (If Sony folks are allowed to be called that), I still believe that many people can be happily served in all of their photographic needs and for a lot less money and grief with a nice P&S! Not everyone needs to print posters, works for Nat'l Geo, or strives to be Galen Rowell or open a gallery. Some folks want an easy, convenient, but capable camera to help them take good photos and give them a little room to learn...and will share them onscreen or in small to moderate prints with family and friends.
.