I just want to point out that if Snowden would have been spying for Russia or China, he would not have any these problems. Countries don't return people who spy for them.
His knowledge is very likely still valuable and he could turn into traitor any day and Russia would take good care of him. He would get money, pension, citizenship and nice Datcha to live in. He is this predicament because he has not given up his principles.
The notion that defectors are lavishly rewarded -- a notion that Snowden encouraged in his comment about palaces and petting a phoenix -- is at odds with the historical record. Consider Kim Philby. After the act of defection has been milked for propaganda, the defector is dispatched to guarded obscurity.
It's hard to know what's really happening between Snowden and his hosts. The notion that Russia's hands are legally tied and that Snowden is just hanging out at the airport as a logistically challenged but ultimately free agent is absurd, but it's understandable why Russia is staging that diplomatic farce.
As for Snowden's role, if he has valuable knowledge and he has not "given up his principles" -- so much the worse for him. He'll get a chance to reconsider the boast that he "cannot be coerced into revealing that information, even under torture." It could have already happened, with the bit about resisting torture ghost-written by amused interrogators.
His knowledge is very likely still valuable and he could turn into traitor any day and Russia would take good care of him. He would get money, pension, citizenship and nice Datcha to live in. He is this predicament because he has not given up his principles.