Hehe, since the start of the summer, I've played Chrono Trigger and Secret of Mana on my Xbox using the SNES emulators, and I've played Final Fantasy 7, 8, and 9 (all PS1 games) on my PS2. It's not that I don't have a SNES or a PS1 since I do, but to me its strictly an issue of convenience.
But like you were saying, Xbox 1 games aren't gonna be as much of a graphics jump to Xbox 2 as like SNES to N64 was. But along with that, its MUCH harder to design and build and Xbox2 with an Xbox1 inside of it. I mean, have you played like Goldeneye 64 on your Xbox? It runs like crap, all slow, but ofcourse you would think, Xbox is 5x faster than N64 but it does not work that way, they are completley different designs, as the Xbox1 will be to the Xbox2 probably. Ofcourse PS2 pulled it off nicely, but if it comes down to an issue of price, I don't know if I really want backwards compatibility, because i probably won't put away my Xbox 1 anyways (Xbox 2 does have a HD, thats half the fun hehehe).