I think the last team to win back to back was Milan 89/90 so its been nearly 20 years and back in those days you only had one team from each country.
However I think Man U can win. Liverpool are overrated and will lose sooner or later - along with Porto, Villareal and Munich. That leaves Barca, Chelsea, Man U or Arsenal which potentially have the quality. I'll say it even though its obvious but Barca & Man U are most likely because of Messi & Ronaldo. Would be great to see those two in the final
However I think Man U can win. Liverpool are overrated and will lose sooner or later - along with Porto, Villareal and Munich. That leaves Barca, Chelsea, Man U or Arsenal which potentially have the quality. I'll say it even though its obvious but Barca & Man U are most likely because of Messi & Ronaldo. Would be great to see those two in the final