Completely the wrong decision in my eyes. AVB had potential to turn the club around, and was given not enough time. Any manger coming into Chelsea has to a) play the ageing players who aren't going to play every game of every week, they just aren't cut out for it anymore or b) tell them where they stand (to which my knowledge AVB did) that they need to accept a different role now where they are more mentors and play less regularly. Either way the manger risks dropping points on poor performance or a dressing room revolt. I don't see how it's going to work other than 2-3 seasons of one manager rebuilding a squad he can work with.
Both Liverpool and Manchester United have shown how the main men of yesteryear have gone onto accept a different kind of role in the team. Carragher, Giggs and Scholes and slowly Gerrard and Ferdinand are coming to a role where they don't play every game every week, they've done there job on the front-line and it's time to sit back and give the orders, coach the team and step in when needed.
I also think Chelsea's downfall has been not making the right decisions when signing new players. To me personally I've always felt they've gone for the headline signing Shevchenko and Torres etc. Rather than constantly bringing wave after wave of talent each season like other clubs and I think City might learn from this and not sign the big name but the lesser known talent and bring them through, I think we're beginning to see that with Ballotelli, with a bit of an attitude change he'll be a great player.
That's just my opinion on the whole saga. Not enough patience at all.
And Di Matteo is in a win-win situation, he does anything remotely good, he's turned the team round. If the poor performance continues he's inherited AVB's 'squad'