I think you should post your suggestion http://www.gamesas.com/index.php?/topic/1100256-what-do-you-want-in-new-vegas/ instead.
Yep, that's the best place to request things like this
How difficult would it be to update the animations? The walking animations look so dated that it really takes away from the total game. Everything looks so good with this game and when you have something so out of place it really stands out. I was kind of hoping that they would have updated this part of the game. Oh, well. Surely Elder Scrolls V will have new animations.
Obsidian may be tweaking/updating old animations but I don't see them adding a whole new animation system like the physics-based animations that some games have.
As for Bethesda's next game, it's certainly possible that it will have a brand new engine but then it's also possible that they'll try to get one last game out on this tech generation in which case they'd probably be using a further upgraded version of their TESIV/FO3 engine.