Unless you are planning an event that is relying solely on people traveling to get there, then you have to take your local area/city into account to determine how popular a bbPress and/or BuddyPress camp would be.

For BuddyCamp Miami, we surveyed months earlier to determine if it was solely going to be BuddyPress related or if it's a mixture of bbPress and BuddyPress. At that time, very few choose bbPress. That's just for Miami at that time though, and wondering if non-developers wrote it off as "just forum software".

I think you should have a "bbRetreat" where developers and designers can attend a small "camp" focused on bbPress and BuddyPress, contribute patches, etc. Make it an annual or semi-annual event, find host cities, etc.