Obama is much too vane to step down, he will be president for life I'm afraid!
No, he will not, at least not beyond his eight years (God forbid) and hopefully not beyond four. Will will neuter this quisling in 2010 and then run him and his out on a rail in 2012.
If he tries anything extra-constitutinally, he will open up a can of worms he will wish by God he had never even thought of.
There are Oathkeepers who have already made it plain to him and others what orders they will not obey.