The Wii's marvelous success against the more (horse)powerful competition shows that the gaming audience in general doesn't care a great deal about who has the best graphics. This might change if HDTV actually achieves a decent adoption rate during the next 4-5 years or so, but the Wii has a good chance of breaking the tradition in this respect as well.
I imagine Sony and Microsoft would also be rather keen on keeping their consoles on the market for a while to actually earn some money on them. This means anyone willing to take a risk could launch way earlier than the competition, but I think Microsoft wouldn't want to go through all that hassle again, and no developer would trust Sony enough to make exclusives.







