I don't think it's a good move for either party. Aguero is a striker and not a winger. Chelsea desperately needs naturally wingers, not strikers playing on the wing (such as Anelka). Which is why I'll be depressed if he ends up there. If he goes to ManCity I could see him getting stuck behind Balotelli, Dzeko, even Adebayor...he's better than all of those guys but all of them are better suited to the Prem and ManCity's and Mancini's style.
Really, really hoping he goes to Barca or Milan. I'd be absolutely thrilled if he went to Barca and I actually think he would put Villa on the bench but from what I hear they're going for Rossi, who's cheaper (what a terrible move, means they're spending 30 million on a bench player or putting Villa, who they spent 30 million on last summer, on the bench, Roselle is a complete idiot).