The important thing is you're using promises. The differences between Q and Bluebird are minimal, compared to promises vs raw callbacks.
I just found this after some cursory Googling and haven't tried it at all, but it appears to be a compatibility layer for Q on top of Bluebird (written by the author of Bluebird): https://gist.github.com/petkaantonov/8363789
Yeah, for the work we're doing, promises are awesome. I've been doing node work recently and really it's the only thing I've seen that makes sense to me for managing this.
It's interesting--I'd considered myself pretty OO in my style, pass a message, hope for the best, but the promises stuff is kind of taking that to its natural conclusion.
I just found this after some cursory Googling and haven't tried it at all, but it appears to be a compatibility layer for Q on top of Bluebird (written by the author of Bluebird): https://gist.github.com/petkaantonov/8363789