I'm skeptical about Bethesda's competence, but I'm going to buy it anyway.
First of all, they don't do DRM runarounds. That makes me, and my wallet in turn, very happy.
Second, I hope with all their talk of "listening to the community", they understand what went terribly, disgustingly wrong with Oblivion. The severely limited number of voice-actors. The world background and various storylines that fell flat because they were elaborate enough, but boring. The enormous world that gave no incentive to explore. The weird equipment/difficulty curve that encourages players to stay at level 2. So far, the only concern I haven't seen addressed when reading about Fallout 3 is making sure the damn thing doesn't crash and corrupt saves every 5 minutes.
Lastly, the Fallout universe is not very rigid. Its main components are the visual styles and humor elements, and a bit of good/evil decisionmaking that is not crucial but does affect the world. There's very little storyline to adhere to, and all the people and events of previous games are so far away they'll have little impact on this setting.
So... I'll bite. I figure they can't screw it up too badly.