He and his crew will punish the USA with many bits of sabotage from Pardoning all or most from Gitmo to selling pardons for his new life in Hawaii. They will trash the White House and do all he can to make Romney a failed president. Watch him speak out and carp from the sidelines—as his motley crew writes book after book showing his corruption and failures. In time he will be not looked upon well by history.
Obama won't have the luxury of living the lavish lifestyle in Hawaii if he sullies his name with pardons and endangers America with the closing of Gitmo. Look at Clinton. He more or less left office with less than a good reputation, yet was able to rebuild his image to the point he would win in a landslide if he could run again.
Obama will play by the rules of transition so that he can keep his options open. If he were to create havoc after his defeat, Congress could strip him of the post-election benefits presidents get. That would pretty much destroy him, and his cronies in Congress who enabled him.