Oculus may be the leader, but they're certainly not the only game in town.

Jeri Ellsworth (Technical Illusions) with the CastAR, Sony has one, GameFace Labs, Durovis, etc. are all competitors.

Even if Oculus is the best thing out there, their advances will quickly spread to the community. With the competition we're seeing in the area, it's going to be very crowded, I don't think Oculus being bought by Facebook is bad for consumers. It could be bad for Oculus, but it's not like Facebook is against open source (just look at their github), so I don't think we need to worry about them trying to squirrel away every advancement they make behind a patent or anything.