Although Solo/Group content is good for some players, a lot of us play for raid sake. I know my guild is making a final push through the last tiers of the available content. We'll be eagerly looking for the new content. The Adventure system on normal is incredibly easy, basic level 70s can acquire the BEST gear in the game . . .All either 2boxing or even doing 1 toon and 1 bot. I think developing Solo and small group content will hurt a large group of players.
I voted for 12 man stuff. Make some friends and plan some raid times and you can do things!