I read on the internet earlier that fallout 4 might be released end of 2012 and there's already a teaser trailer of it (not sure if its real or not). If thats the case the next gen consoles are supposedly scheduled for 2016 which would be roughly when the next TES should be ready.
TES VI might be the one of the first releases!
Source or link?
Fallout 4 will not be released at the end of 2012 simple as, Bethesda will still be supporting Skyrim with dlc at that point and I find it extremely unlikely Beth will release 2 huge games like that only a year apart.
No source for this but common sense says Fallout 4 won't be with us till 2014 at the earliest. Anyone want to prove me wrong feel free.