bbPress straight out of the box is not suitable as a large social network style forum such as what the WordPress.org forums should (presumably) be. But they also don't need anything like vBulletin as that would simply be adding bloat to the system. A few basic plugins would solve most of the problems which make the WordPress.org support forums so awful. I don't think they have any intention of making anything to compete with vBulletin as bbPress is niche product.

It sure would be nice if they made their own support forum a lot better though (with plugins) as it truly is a horrid little forum in it's current format and it doesn't seem to attract many people to come and help. I've tried offering help there before and just got ticked off at the lack of tools/rules etc. at hand. I couldn't even find a way to report a post, apparently you need to add a tag to the post to do that, which IMO is a ridiculous thing to expect your users to do.