Yes, Obama will close GITMO in his second term. Obama is all about pleasing the left and he will close GITMO in a way to keep them on his good side. If he keeps the left on his side, he gains additional positive sentiment from the masses, which will allow him to continue to push his liberal agenda.
Now that he has been re-elected, I think that Obama will have the power and courage to push back against the conservative sectors of America and make changes to our "war on terror". I think that he will be under pressure from not only Democrats, but international agencies that disagree with the actions at Gitmo.
The war on terror continues and there are not very good places to put the prisoners. Some of those released previously have rejoined terrorist groups. This makes release unlikely. GITMO is relatively secure and not on the United States mainland. I do not see a better place for the terrorists to be incarcerated.
While I do think he was sincere in wanting to, we've seen how slow things get done in Washington lately, if at all. This isn't high on the priority list at the moment, so with those two factors combined I'd be surprised if he even got around to attempting to do so, much less accomplishing it.