The 20D is obsolete only in the fact that you can no longer buy one NIB. Canon is basicly on a 18 month cycle for new modles and they are bit a bit of a technological odd duck in the sense that they frequently introduce the newest technology on their lower end products. If it flies then they use it on the better cameras after it's proven. This is one of the reasons that I would stick with the XTi even over the 30D but that is subject solely to personal preference and price point. For some one starting out I'd still suggest the XTi over the 40D as the price difference buys a nice piece of glass.
