If you had asked a few days ago I would have said that Inter would be the favourite in the semi-finals against Barcelona, as Barça is showing signs of serious fatigue. But with Inter's losing streak, having less rest time ~~and Thuram missing for the first leg~~, I think Barça will go trough.
Arsenal - PSG is harder to predict as I don't follow either team. PSG have been slipping lately, but that could just be to having nothing to play for in the league. I think Enrique got it, PSG - Barcelona in the final, which Barça obviously will win.
Athletic Bilbao plays against Manchester United in the semi-finals so I'm fairly confident they won't face each other in the final. Regardless, it's obvious that the Norwegian giant Bodø/Glimt will win the whole competition.