Wiggins said he doesn't ever want to put in the time to win the TDF again. He can challenge the Giro or Vuelta, and Froome focuses on the TDF. Richie Porte will probably get the shaft next season and not be a team leader. One thing to keep in mind last year Froome finished second and could have easily won. Porte buried himself a couple of times to help Froome, but he also had a couple of really bad days and lost big time. He'll need to be more consistant to usurp Froome as the GC man for Sky.
Also Sky has tons of money in their bank account, like the Yankee's their concern needs to be keeping everyone happy not their balance sheet.