Damn! I've never been on this thread before; I was hoping for some info on this very match. At least tell me who to bet on!
Two very evenly matched teams Jazzmoose, both have massive squads (internationals regularly sit on the bench) which allow them to play at a frenetic pace and contest every ball all over the pitch. Not always pretty, but quite compelling and very effective, thus their success.
Personally, I think United have the better individual talent and are a more potent attacking force (the scored 15 more goals the 2nd placed Chelsea in the Premier League) so my money would be on a close game with United winning by one goal.