Inter will most likely sit back for both matches. One would think Mourinho would learn from his mistakes, but potentially not. Perhaps 1-1 or 0-0 with a side going through on away goals because Barca won't have an easy time breaking down that defense. But we've seen this before... Barca usually finds a way to break down those sort of sides, whether it be Chelsea or Inter. The latter will have to hope that they will face Marquez and Milito because if they will then I'd bet on Inter. Otherwise, Barca should progress.
Arsenal and other sides have shown that to beat Barca, you have to take the game to them. No sitting back.