I'm not gonna lie, as much as I like the Prison of Elder idea (from what we "know" so far), I'm gonna miss my 6-man fireteam. Been running VoG and CE with pretty much the same people since the game came out, and as much as we're excited about this new thing Bungie's providing us with, we're pretty bummed to split our group in two. That said, what about the idea of adding a bit more flexibility to the size of our fireteam in PoE? Make the thing scale based on the number of people in the fireteam. Let's say a minimum of 3 player, up to 6. Balancing issues aside, WoW as toyed with the idea of raids accomodating parties of varying sizes, and with a lot of success. I'm not saying it'd be as easy as flipping a switch, but expanding the idea of a horde mode with bigger teams seems to me like a promising idea.