These consoles are not really anymore ahead of their time than the XBox, Gamecube, PS2, Dreamcast, N64, Playstation or Saturn were ... What will really determine when the next generation begins is how third party publishers are reacting to the sales of the current generation of consoles.
It is very difficult to say what is currently happening with third party publishers because (as a consumer) there is a lag between them changing their policies and it being noticeable in upcomming releases; but I think it is safe to assume that the low cost of development and high sales for the Wii are having a considerable impact on their plans. With how long it takes to develop a HD game (mostly 2 to 3 years) publishers would have to see some reason why they should devote the massive resources towards HD games in the next 6 months for these systems to have many games in 2011 ...
Personally, I don't see that happening and I expect that Sony and Microsoft would rather release a new system in 2010/2011 then watch their system have no game releases for 12 to 18 months.
