This is an extremely foolish thread because absent some completely almost unimaginable horrific event, US Airways will be with us in 12 months. You can book with absolute confidence that the airline will exist. They have ample resources to survive -- and possible thrive -- in the next 12 months.
That said, I recall a situation when US's future was WAY less certain. Folks may remember that before the America West purchase/merger, there was a real chance that US might go away. Many flyertalkers (like me!) were redeeming their Dividend Miles to fly other airlines, to avoid losing the miles if things went south. I remember booking tickets to Hawaii on UA at that time. I sent an email to UA customer service asking if my tickets would still be valid if US went under. They SPECIFICALLY said they would honor them.
No guarantee that would be the case these days, or with different airlines, but that's what I was told about 5 years ago.