I think it's fair to say, a lot of people are looking forward to FO4, and of the Bethesda RPGs, New Vegas was pretty shaky until they got a good couple of patches in (I know it was developed by Obsidian).
Also, from the reveal trailer alone, that damn curtain model and texture is still there along with the same "broken floor tiles" texture. I'm hoping we don't still have rain piercing through solid buildings/roofs/overhangs. I mean, I welcomed the rain in Honest Hearts, I love dynamic weather systems like Just Cause 2 did. They really add a lot of atmosphere to the game.
Would be awesome if Mirelurks became more aggressive and gained health regen in the rain too. How weather might actually affect gameplay and combat...