Its difficult to predict how Mclaren will do next season? First they need to prove to the FIA that their car has no Ferrari type intelligence and material in their cars. Thats going to be extremely difficult, and imo they'll have to make a completely new car to convince the bosses.
Reliability was always as issue at Mclaren until this season, and if they do develop a new car, it might once again creep back in. Also Hamilton dint have much pressure when he started the season, but come next year, a lot will be expected of him, since he will be the number one driver for his team.
Dont know where Alonso will go with huge financial backing, but the team that makes the most out of this split is obviously Ferrari, and I see Raikkonen or Massa winning the title next season as well.