I'm pretty sure Nomad Captain America is still running around claiming he's the real Captain America, but no one is listening still. I'm pretty sure he's still doing the government's dirty work with the New Invaders, they just don't have a comic. As for Bucky, man have you been away for a while:
It was revealed that Bucky was sent on a covert mission to the Soviet Union shortly after WWII. He was captured and presumed dead. Instead, though, the Soviet Union spent years brainwashing him and made him their own agent. Recently he has resurfaced with his memories returned to him and since the Soviet Union is no more he is no longer under their control.
During Civil War 2 years ago, Steve Rogers (Original Captain America) led the anti-registration heroes against Iron Man and the pro-registration heroes. He was assasinated (not by Iron Man or his allies, though) as he surrended for the safety of the american public. Afterwards Bucky reluctantly took Steve's place as Captain America and is the current Captain America you now see in the new Alex Ross designed costume.