An ideal world:
Hart starts passing the ball from the back a la Valdes, Casillas, Reina.
We have a centre back who is more comfortable on the ball next to Kompany, and isn't as rigid as Lescott in that he's prepared to take it forward when the opposition haven't yet shuffled across to the side of the pitch where the centre back has the ball. I do like Lescott though and had a lot of faith in him when plenty wanted to get rid of him.
Clichy making runs to get in down the wing similar to what Richards does.
Yaya is prepared to get back behind the ball more when we've not got it and gets rid of his rare horror show performances like against Bayern Munich and Chelsea away.
We get in a world class right/left midfielder who can come inside but not to the extent that Dave does when he's playing on the other side of midfield. This would complement the work that Dave does, but would not leave us with only one man in Aguero (because I'd like us to play 5 in midfield against the top teams) or just two men against the lesser teams (Aguero and Dzeko) playing on the shoulder of the defender and would not make us too narrow. If we got him on the left wing, the point I made about Clichy wouldn't apply as much. Also, if Silva was shifted to the right to play with Micah then wouldn't be that far away to what Alves and Messi have got.
Oh, and De Jong to lose some weight because I think he's an automatic starter if we were to play Barcelona or Real, and I think he's a top asset to have.
I don't want this to come across spoilt either. I hate talk about players who aren't here, and I can count on one hand the times I've been in the transfer forum, so the emphasis is on 'in an ideal world'. These changes only need to be made if we're serious about competing with the Spanish teams.