The majority of any soundtrack is in the front 3 channels. No question about it.
Even when they come out with discrete 11.2, I'll still think it is pure gimmick, just like 3D video.
Unless the room is just very large, I don't see much point of having a bunch of discrete surrounds.
I rather have 5 better quality speakers than 7 lesser quality speakers due to budget limit.
I think the most important thing is in front of us, not behind us.