Were Mancini working for Abramovich he'd be toast by now. But, then again, he might have been toast before City won the League.
Abramovich is after the One Big Thing. He thinks that somewhere out there is a manager who will fix everything. He had that with Mourinho and the thinks he can have it again with the man one Chelsea fan calls Peppy O'Guardioli. There is, however, a small catch, which is that Abramovich thinks he can pick a better side than any manager, and that includes Mourinho, and that he, Abramovich, has second sight when it comes to transfers despite fifty million reasons for him to think otherwise.
Benitez was looking for a job and Guardiola is not. If Guardiola returns to management he can pick and choose - the top Italian or German clubs might sign him, or, more pertinently, Manchester City, (who take a longer term view), might offer him The Contract Of All Contracts. Guardiola is in the perfect position to say to Chelsea 'fine, pay me zillions, and, by the way, Torres goes'. Which leaves Benitez in post, saddled with an owner picking the team. And, given Benitez' level of (justified) pride that's going to be interesting to watch.
There is only one way out of this for Abramovich. Re-hire Mourinho and shut up.