Very exciting this one. I think the thing that may decide it for Bayern is Lahm vs Ronaldo. Lahm has got the better of him every time they met. Meanwhile you could imagine Bayern's wingers tearing the Madrid fullbacks a new one. Arbeloa and Marcelo/Coentrao vs Robben and Ribery? Only one winner there. Obviously Alaba or whoever plays left back for Bayern may struggle against Di Maria, but Bayern will have greater possession and so Di Maria may be penned back defending against Ribery.
Midfield is fairly even, but if Schweinsteiger plays Bayern will control possession, Madrid just don't have anyone who can stop him.
Then it comes down to Benzema/Ozil against Badstuber/Boateng and Muller/Gomez against Pepe/Ramos. I would say advantage Madrid there, but not by much and Gomez is good enough to beat those Madrid defenders.
Too close to call imo, but can't wait.