So the USA CEO is going to run the new airline but they are going to call it American. I would assume they will stay on One World since United is on Star Alliance and they would be the only US carrier on One World (American already is). Star Alliance is much better imo for travel to Europe and low level award availability. USA, Lufty, Swiss, Air Canada and United all have great availability from Europe to the US. So, if you are wanting to go to Europe on US Air miles I'd plan to book that by late this year. They will probably give some kind of lead up to their leaving Star Alliance and not just shut the door at some unannounced date though. I'm currently sitting on about 180k US Air miles and about 200k AA. I'll probably book the Maui Invitational with the AA miles and drag out the USA to the last minute and book something to Europe.