Gonna hijack this thread to post some ideas I've had regarding making the Crucible factions much more important/interesting/meaningful.
CAVEAT - These are ideas that would obviously be released as a major content update or even in an expansion. I do not expect this to be a minor patch. Also, they're just ideas I think would be cool. I do not expect this to actually happen.
All weapons purchased from faction vendors have a final upgrade slot that requires a single exotic material, similar to Necrochasm, unique to its faction.
Upon reaching rank X with Y faction you will be mailed an exotic upgrade material unique to that faction (e.g. Chaotic Core - FWC, Illustrious Core - NM, Despondent Core - DO).
The player will only receive this exotic upgrade material ONCE per character when they reach rank X with Y faction (reaching rank X with a 2nd faction - on that same character - will not give another material).
3 factions, 3 character slots - can get all 3 if so desired
This offers players several options in obtaining exotic faction weapons:
etc
Like I said, this would be a lot of work for Bungie to do and I don't expect it to actually happen. This is just a hypothetical example of how I would like the factions to be represented in Destiny. I just want factions to matter in some significant way.