Looking at Obsidians past games, I think they could have potential, or then again, maybe not. FoNV is by far their best game evah and the games before that were just a bit.. you know.
But, if Obsidian did something similar to Skyrim compared to Oblivion that they managed to do with FoNV compared to Fo3, then it might be a bit smaller game, focusing on one thing only, the main quest.