I only heard part of Tito's presser driving home from dinner. He painted it as kind of a mutual decision - that as he discussed some of the changes that needed to go on with the team, he felt that they would be better off with someone new to lead them. Sounds like the veterans basically stopped listening to him and engaged in bad behavior that he could not control.
There was the Hick White Pitching Clique - Beckett, Lackey, and Lester - along with occasionally Varitek. Many stories about pitchers having beers in the clubhouse during games on days they were not pitching. Youkilis apparently was a little to free with expressing his views on things while he hung around rehabbing. He was openly critical last year of Ellsbury going off to Arizona to rehab rather than being with the team, but Youk's over-the-top competitive attitude was pretty off putting and undermined Ellsbury so much in the clubhouse that Ellsbury would only confide in Jed Lowrie.
Francona said that the team was not reacting the way he wanted to his leadership, without fingering any individual.
As for candidates there, weei (team radio station) speculates most are AAA /bench coach types - Dave Martinez, DeMarlo Hale, Ryne Sandberg, Torry Lovullo, John Gibbons (former Toronto Mgr who is the bench coach in KC), Tim Bogar (current 3B coach), with Valentine being the only prominent retread. Francona, on the other hand, makes sense for ChiSox, I think. I think he is better for an AL team than the NL. In the AL, it is more about season managing than in game moves. Until this year, Francona was known for his ability to keep his clubhouse together.
I'm beginning to think John Lackey is a carcinogen.