Fight your way out; only scrubs and mashers jump out of the corner
Bungie.net already sort of does this with the concept of forum groups, which is about as far as I think it should go.
Realistically, Bungie hosting arbitrary sites makes no sense given their core competency: telling compelling stories through video games.
I mean, would it really aid Bungie or give them any credibility if "ilovecats.bungie.net" existed?