I have mixed feelings about Obsidian...sometimes they do great work I enjoyed NWN2 and KOTOR2 but they fluffed the ending of KOTOR2 because of deadlines. Then there is the widely criticised Alpha Protocol which appears to be a steaming pile of donkey doo.
Opinions are going to vary widely here. Despite some issues (which I hear tell are being patched as we speak) I like Alpha Protocol. It has some shortcomings, yes, but I personally feel that most of the things it's been criticized for by the "gaming press" are pretty superficial, and in my experience most of the people commenting online haven't even played the game and are just parroting reviews they've read.
It was a very ambitious game. To me it feels like they just ran out of time to finish things in some areas. For example, it's missing some of the types of lighting effects people are used to seeing in modern games, which can have a pretty noticeable effect on a game's "graphical ambiance." To me this is pretty minor, but to others it's a "OMG teh bad grafx" situation. Yes, the sneaking character animation looks goofy.. Other issues like unbalanced skills and occasionally strange AI behavior are, to me, overlookable. There are a lot of other aspects of AP's gameplay that are fun enough that I'm having a good time with it while I wait for a patch.
If anything, playing AP has made me more optimistic about New Vegas. If Obsidian can build on Fallout 3 and add some of AP's gameplay, story, and dialog depth I feel it will be a significant improvement. Just my opinion, of course.