I think we need more work than you'd expect a title winning team to need.
Vidic and Ferdinand are great but creaking. I personally wouldn't trust Phil Jones, or Smalling yet. Evans has been decent but paired with one of the latter two he starts to look suspect again.
Left back as identified is a problem, but I'd rather we bought a young player to develop into replacing Evra than going balls out for a player that will need replacing again in a few years.
Right back and goalkeeper is fine.
Midfield - Carrick is 32. Everyone else is average, Cleverley included.
Wingers - all of them were terrible last season. In a way that's good because they can't be that bad again but I cringe when I see Valencia, Nani or Young is starting a game.
Strikers - well stocked, but if Rooney goes, and Van Persie gets injured, or when he starts to decline we'll be relying on Hernandez and Welbeck which is a little frightening.
I'd like to see us sign some midfielders deep lying and some attacking ones that are better on the ball and don't give it away as much. Against the better teams we struggle to retain possession, which is something I'd rather see us focus on improving.