I seriously doubt Obama is now completely unconcerned with his future in politics. He's much to young to hail mary his second term like this and there's no precedent that would indicate anything of to sort. Also, he's going to be focused on winning back the house in 2014. As it stands, he's in for more gridlock over the next 2 years given the split in congress.
Remember, this is the same guy that supported the NDAA, has increased drone usage both locally and abroad, and didn't take to well to the whole Bradley Manning/wikileaks deal (also, what was his stance on sopa/pipa). Obama is only for "open government" to the extent that it furthers his party's agenda.
Does any ex-president have a political career? Where would they go from the top? He's never going to have as much power and ability to make difference as 2nd term US President. It's now or never.
Ex-presidents do a lot of work that goes unreported once they leave the white house. They typically work directly with the president who's currently in charge on foreign affairs by meeting with dignitaries, they assist with humanitarian efforts, they work as part of the national convention (John Kerry and Jimmy Carter assisted Obama with his speeches and debates), and so on. Just because they aren't in the white house, doesn't mean they aren't active in politics. These guys have experience that is extremely valuable to anyone who's currently in or is trying to get to the white house. Also, remember that it takes a certain type of person to be president. Most of these guys would go insane if they just went back to their ranch once they left.
The President's Club is a great book that covers some of the ways ex-presidents stay involved in the politics of the day, even if you don't hear or read about it in the news.
My argument is that if it's something he things is good for the public, but could damage his status within his party or his party's opinion in the eyes of the public, he sill won't do it.
Remember, this is the same guy that supported the NDAA, has increased drone usage both locally and abroad, and didn't take to well to the whole Bradley Manning/wikileaks deal (also, what was his stance on sopa/pipa). Obama is only for "open government" to the extent that it furthers his party's agenda.