I was in some camera thread a year ago getting great advice; ended up buying a Canon Powershot (SX10?) which was fine. However, the delay time is killing me and along with that, my interest has grown and I want to upgrade.
So at Thanksgiving, I picked up someone's D90 and took a bunch of pics that night. Man did they turn out great and I could tell the difference in quality just using it.
So at this point, which DSLR should I get is the question?
I'm just beyond the phase that you're in. Just upgrading from a P&S to a DSLR. I did some research and ended up looking at it like I look at buying a driver in golf. You can buy the hottest, newest model driver for $500 or you can buy the hottest, newest driver from 2-years ago for $200--and it will do 99% of what the current models can. So, if you want to save a few bucks you can get a pretty good deal on the second-to-last generation. Also, from what I understand, if you want to spend the extra money you should spend it on another lens rather than incremental capabilities on your camera body.
You make a good point about being able to get another lens with the price difference and that is certainly a selling point.
However, I think with technological advances you are underselling it a bit if you compare it to performance advances with sporting equipment. Technological advances happen much faster and are much greater than performance advances. I am usually of the mindset to buy the best computer/camera that you can afford because there is a noticeable difference.
You are going to be able to get pictures with the D7000 that you are just not going to be able to get with the D90. Having a higher ISO range opens up the possibilities so if you are serious about shooting pictures this is a pretty big difference. The comparisons are already in with the D7000 matching up pretty well with the much more expensive D700, to me this is a huge selling point.
But to get back to your original point with having versatile lenses, that is very important too, which is why this hobby can get so expensive.