Space Ace's comments about the Treehouses being great for gatherings got me wondering. If you were having a "gathering" what are some good on-site locations? Both from a savings perspective and an AWESOMENESS perspective? DVC sites seem like a likely candidate, but has anyone had any other thoughts?
For your best value I'd say maybe adjoining rooms at Coronado Springs, but you'd probably do even better at Old Key West or Saratoga Springs Villas. They seem to have good deals there too, so that's probably my vote.
For "awesomeness" I think I'd go with Wilderness Lodge Villas.
Agreed that OKW and SSR are always gonna have the cheapest options for big groups. Nobody wants to stay there because they're so out of the way, so they're always running deals and discounts on rooms.
May 2008 CSR 
The more I look into it the more I think the Treehouses may max out on the awesomeness scale...
Based on the renderings the Treehouses look can't-miss.
Based on the renderings the Treehouses look can't-miss.
Lots of places are "can't-miss" if you disregard price!
Well much like Fort Wilderness, the price may look high until you think about how many people you can get in there.
Brad's and dsoup's points make sense. Price and number of people you can cram into a space are definitely factors for a group gathering.
I think the treehouses are going to be incredible, but I'm not so sure I'd want my whole extended family packed into one place for an entire WDW vacation. I need that "everyone-goes-to-their-own-room-and-closes-the-door" rest time at night. 
I should work up a spreadsheet to see how many people you have to fit into say some kind of "Villa" to stay cheaper than one of the value resorts.