I wouldn't mind Capello staying, but if there's gonna be a change in management, here are my thoughts on the subject:
Guus Hiddink is probably the safest bet, you just know we're gonna be a competitive side with him as manager. Nuff said.
Spalletti is doing great in Rome, but to me he is still a bit unproven and I just feel it would be a huge gamble to bring him in.
Prandelli would be better in my opinion because I think he's had more influence in Firenze than Spalletti's had in Rome. We must keep in mind that Roma are better on paper, they have many world class players in their squad, still; Fiorentina will get that 4th place, I'm sure of it.
As for Vialli it's way too soon, and I really don't see people like Deschamps or Lippi taking over, the latter simply because he's had his time here.
1. Hiddink
2. Prandelli
3. Spalletti