To preempt any 'TESV 4 nextgen consoles!!1,' I don't think we should extrapolate too much on the "next generation consoles." As has been said, Sony and Microsoft are quite satisfied with the 360 and the PS3 at least for a while, as evidenced by there development of the motion controllers. Their reps have even said this explicitly in interviews. Next-gen consoles probably won't be coming out for at least a few more years (at the earliest). Likely to be several more years. So, TESV will likely be for the current-gen ones.
That is, unless of course Bethesda wants to wait on TESV for yet another four more years...
Expect news of new consoles at E3 2011, possibly earlier for the Wii's successor (Nintendo trademarked the name 'Zii' just before christmas 2009, for hardware purposes, and it clearly isn't the next gameboy with the recent announcement of the 3DS). Don't
ever believe what Sony and M$ say about their next hardware iterations - those designs and progresses are their
biggest kept secrets. If Sony says: "
no PS4 for the next few years at the earliest", then I guarantee M$ think: "
there's a free hole in the market!", and vice versa. These guys do not play fair with each other, and do not honestly express their business plans to the public. Just like how Oblivion was firmly denied up until its announcement, the next gen of consoles will be firmly denied until their's. 2011 announces are likely, with 2013 releases at the latest. We're already into the 360's 5th year, and a console's support and lifespan (10-years being a popular term) doesn't end when the next iteration is released (PS2s are still on store shelves to this day). 2013 would mark an 8-year reign for the 360, when the PS2 had a 6-year reign before the current-gen began.
With that knowledge in mind, don't forget that the twilight years of a console often provide its best games. A new console announcement won't lead to a sudden halt of game production for the current-gen. Todd Howard specifically stated that he intends to release another TES game on this generation around Oblivion's launch, and as many people have pointed out with Red Dead Redemption: the current-gen can offer a lot more than Oblivion brought to the table. We all know Bethesda can provide.