I'll be 1P for next year but I'm probably a natural 2P. I'm thinking Air Canada. That way I get *G benefits after 35,000 miles (which I do easily). And all I have to do is to make sure one of my yearly international trips (Australia or Europe) is on AC metal, which isn't overly onerous.
There's also Aegean, but that seems too good to be true, like there must be a catch somewhere. *G benefits flying 20,000 miles a year without ever setting foot on an Aegean plane?
Realistically I'm not sure if I'll even be living in the US by 2013. Hopefully I'll be back in Australia, in which case Virgin Velocity here I come!