I think it's a nice idea. I have left several cake groups on FB because of bad behavior and language on the threads. Although I must admit I had learned a trick or two by the more serious members the pricing complaints or who stole my photo or ideas became more negative than any positive flow from the site.
I also saw on the ICES forum they have a time when people can exchange cookies and cutters and other double tools they bring along. I though ,how fun is that. Not to turn any discussion into someones sales corner but to have a Exchange forum for someone that has 10 of the same cutter and might shout it out on that forum. Just a thought.
This is the concern I have about a social forum. If one is added, it will be governed by all the same policies and procedures applied elsewhere. I don't want it to degrade into a spot to vent and complain in any way. Nor do I want it to become a clearinghouse for sharing personal business (that can be done in private Dialogs) and personal photos (the latter are prohibited due to childhood privacy laws). Fun cookie topics, like an exchange and some of the other things that Butterwinks mentioned, seem like they'd be constructive though.