A scenario. The regime will continue to fight for control of the supply lines that run from Damascus to Homs, Hama, Idlib, and Aleppo. As it does so, it will lose more territory to the north and east of Aleppo. The vice will eventually close on the city, and it will fall to the FSA.
And if Aleppo falls, this war is over. Assad will then lose all of Idlib Province --- which has in effect already happened --- then Hama, then Homs.
In short, unless there is a surprising change in the course of this fight, every indication is that the President Assad cannot win this war.