I'm very much hoping that Sasuke's "different" seal is way more powerful than the stupid Sound 4's. I would love to see the foreshadowing come to some kind of fruition.

My prediction: someone other than Kakashi will stop the fight, OR after fighting for some time, there will be a dialog where Naruto finds out how much Sasuke values him as a friend (possibly by Sasuke revealing to him that Mangekyou can only come about by killing your best friend).

-xtortout