Given Kishimoto's writing style, and his propensity for interrupting fights that are in progress, I make this prediction :

Naruto catches up with Sasuke, short conversation, Sasuke refuses to come back, Naruto decides to fight him .. Sasuke goes LvL2, Naruto gets Kyuubified, and then Oro shows up .. and Naruto is defeated/forced to withdraw.

I'd rather see Itachi show up, but it will probably be Oro (possibly Kabuto) .. but whoever does it, you can count on the fight being interrupted prematurely. I think that Kyuubi Naruto > Curse Seal 2 Sasuke, because the curse seal seems like trash, the rest of the Sound sucked both with it and without it .. and Sasuke was pretty weak even with CS1. I don't think CS2 will do much for him other than make him fugly [img]i/expressions/face-icon-small-happy.gif[/img]