Barça will win the Champions League Final
Barcelona have played the most consistently superlative football seen in a long time, and they have done so not only in Spain but also in the Champions League.
The Chelsea-Barça semifinal cannot be seen as an example of why Barça might struggle against ManU. ManU wont be able to play Barça as conservatively as Chelsea did in a one match showdown. Let's not forget that Chelsea hung on for dear life in the Nou Camp and miraculously survived the Barça onslaught. That is the only reason why they almost managed to qualify for the final in the second game.
The Chelsea-Barça semifinal also highlights an important point - the great resiliency that Barça has shown in overcoming adverse scores. They came back to tie Chelsea in the last minute, they beat Real Madrid 2-6 after being down 1-0 in the Bernabeu, and in the King's Cup final they likewise came back to beat Bilbao 1-4 after being down 1-0. This will be a key factor in the final in the hypothetical case that ManU draws first blood, especially if they do so early in the match.
I believe ManU will play a defensive minded game, waiting for the counterattack, hoping to neutralize Xavi and Iniesta and to score late so that Barça wont have a chance of mounting a comeback. This is their best bet. Yet this will mean that Barça will have possession of the ball, and that could very well be a stake to the heart for ManU, for they will be forced to play a perfect game if they want to come out alive.
Barça is simply majestic when they have the ball (and this year this has always been the case, averaging over 70% ball possesion match after match). Furthermore, if the score remains at zero well into the second half, ManU will have to advance their lines in search for the goal. This stretching of the lines will inevitably open up spaces, something which Barça thrives upon.
If, on the other hand, ManU scores early and tightens their lines in hopes of holding the 1-0 advantage, Barça will pound them until they find a leak.
I'm backing 7/4 Barcelona at Ladbrokes (free £25 bet)