Yes, I am a fan of turn based games, but what I'm saying here is I don't see the business sense in this. I understand Obsidian might be willing to take on the project, but Bethesda has absolutely no reason to comply.
Fallout 3 has found new success under the Bethesda format. I don't see them risking that success by allowing a hardcore niche product to come out with the Fallout name. Down the road, maybe the franchise will stagnate a bit and there won't be as much of a risk in outsourcing their major IP, but right now Beth will probably be playing this one close to their chest.