I few years ago I was so guilty of this before I created a strategy for my upgrade. ; This is an excellent article by Thom Hogan on the best time to know when to upgrade the last part of your equipment bag --> The Camera Blame the Equipment You know, I still think I have a couple of buttons I need to figure out how to use on the old gal, Nikon D70 (as I eye the sexy D700).
I do think you can blame the glass, but his article is spot on! But I always get the blue crane DVD for my camera bodies and have the one for e false I have too. ; It is awsme and goes through everything!
My point being is that when you learn techniques and develop the skills to go "oh, i can frame the scene with this" or "I'm going to silhouette that" or "spot meter that shaft of light" using a long lens to compress the foreground or going wide to show all the context of a scene, these are all skills that you can apply to whatever camera you have, be it a film pentax K1000 or a nikon D3s. The principles of light and photography dont discriminate between brand/models of cameras.
I agree with you to a point. ; Since I've had my Nikon D70, sensor technology has taken a huge leap. ; Even the newest, cheapest dSLRs handle noise and color better than my top of the line pro-sumer camera of 5 years ago. ; There are other advancements which I consider worth paying money, too. ; Now, do I go out and buy the latest and greatest every year? ; No, most digital cameras can last as long as any good film camera if taken care of. ; And, as long as software companies keep supporting it which is something that could happen if the manufacturers drop support of the model (IBM is famous for this in the mainframe world).
If ISO 200 = ISO 200, which unfortunately they don't always do so anymore. ; A majority of the principles still apply, but each sensor is different, just like you can't compare MTF charts between manufacturers.....
Scott, my point being is that technique applies to all cameras. ; I'm not talking image quality or any of the technical aspects of what comes out of the camera. ; I'm talking artistry, ; How i frame and compose and layer a picture in a canon camera is the same as how i do it in a nikon camera or with a P&S camera. ; You learn those techniques, you learn how to "make" an picture rather than a simple snapshot and you can make those with any camera. ; Even something as simple as remembering the sunny f/16s rule... its something that applies across the board.