So, not to fuel the debate, but, the 20d is faster, and has less noise than the d70. The only reason to buy a rebel xt over a d70 (not counting already haveing lenses/other accessories) is mirror lockup, which is mysteriously missing from the d70. The d70 does 3 fps for 117 frams, the xt does 3 fps for a whopping 14 frames.
The reason to buy a d70 over a 20d is simply price. The 20d is a superior camera to the d70. A d70 is a better value to a first time dslr user because to get a 20d and a good lense you are looking at &1650 minimum. To get a d70 outfit that comes with an excelent 18-70 f/3.5-4.5G ED IF AF-S you are looking at &1100.
Now being a FIRST TIME SLR user, you have to factor in not only optics like I already have, a minimum of $240 (160 legs + 80 head) for a nice tripod. Factor in about $380 for something like a gitzo mountaineer, or a manfrotto mountaineer + 80 dollars for a magnesium ballhead that is light enough that a n00b will carry it with him/her.
you walk w/ a 20d for:
w/ nice tripod: about 1820
w/ nice light tripod: about 2050
d70:
w/ nice pod: about 1320
w/ nice light pd: about 1550
clearly the d70 is a better value, BUT the 20d is 8 mp, Most people have heard me rant about the difference between 6 and 8 mp being absolutly nothing to influence your decision. I still beleive that, but you do have a slightly better cropping ability w/ 8 mp as opposed to 6. The 20d is also 5 fps, has lower noise than the d70 (noise on 20d @ iso 800 ~ noise on d70 @ iso 400). It also has iso 100 and 3200, which the d70 does not.
as for whether or not the d200 will be comparable to the 30d (if they decide to stick to their naming convention).
OF COURSE IT WILL. every camera is designed to be competative with the other cameras in it's class, whether or not it's one companies 9th generation and another companies 2nd.
as far as the d70 being camera of the year, it was Popular photography's camera of the year for 2004