Played it for about 10 hours so far.
If you were thinking they were gonna make a new, polished Fallout you're gonna be disappointed. All the jank is still there. It's basically Fallout 3 with new locations and new weapons (some of which are very cool.) There are some minor additions like factions that can like/dislike you, books that will add points to skills for a limited amount of time, a new companion interface, etc.
If you liked Fallout 3 and want more, you'll like this.