TL:DR; 343 Industries have been tasked by MS to make something Halo VR, unconfirmed just what that will be, but it's apparently happening.

Personally, this is something I did not expect but did carefully hope for. I'm not sure what we can expect, an actual shooter, a table-top strategy game, purely a model and environment viewer... whatever it is, I'm happy to see it happening. Since 2012 I've been a VR fanatic and well, combining that with my old Halo fandom seems like a match made in heaven. Well, BOLL-heaven at least.