I've said it before on other threads; I really can't see Kubica competing in F1 again. The 'confidence' shown by his manager just smacks to me of blustering.
And I believe that Ferrrari will replace Massa early. He may be a good number two driver, but he's currently too far back to be of much help in the Constructors' championship, which is where the teams get their money.
I think Perez is the most likely candidate, but I'd also like to see Hulkenberg in the frame.
Hulkenburg must be loving the test driver/reserve driver seat...... Perez is starting to tickle my fancy, so is Maldonado....maybe Adrian Sutil