First of all, I would like to congratulate United and their fans. As much as I hate them, have to admit that they've been the best team in England and Europe this season.
Secondly, I dont think Chelsea have treated Avram Grant poorly. He has done well no doubt in terms of results, but not sure how much of a role he actually played in resurrecting the season and the team after Mourinho's exit. End of the day, Chelsea need to think long term, and hence need someone with a decent amount of experience to be able to handle a squad of superstars. However what Chelsea need to do is find that manager and stick with him, which is what should have been done with Mourinho in the first place. Lets face it, Grant just took over what Mourinho had built.
Not too sure about Mancini. Yes he can and has handled another star studded team in Inter Milan, but his style of football is even more defensive than Mourinho's and if I remember correctly, RA, dint like that. And Inter's poor record in Europe doesnt have anything to do with Mancini. They have always underachieved in Europe, its almost like their bogey competition. End of the day, he did win two consecutive domestic league titles for the club, which according to me is the most important thing.
But the good thing about Chelsea is that really started playing well towards the final third of the season, and can hence look forward to keeping that up going into next season.
As far as England goes, no one in the current team would make a good captain (apart from maybe Ferdinand). Rooney still isnt calm enough to lead, and although I admire his talent, needs to do a lot more to be captain. End of the day, England are an average at best side, and have players who are awesome for their clubs, but are pretty useless when it comes to playing for their country.