I don't believe there's any thought being put into changing drivers at Ferrari. On any given day Massa can take pole and win the race. The same can be said for Kimi but I think Kimi has a bit more talent in weaving through traffic.
Just as Rubens was #2 to Michael, I think Massa will eventually become #2 to Kimi. They're both pretty young and will hone their talents as years go by.
When Ross comes back there will be another chapter written for the team.