USAIR's has been cutting back flights, laying off people, so flights have been changing, and they have severely limited flights on which you can redeem your FF miles, at least that's what I'm finding. Plus their prices are out of site. For a ticket next Sept. from PIT to MCO. USAIR's price was $1110, and Delta's was $210...go figure!
I fly US Air every week so here are my 2 cents.
1. I've had no trouble with FF availability even since the bankruptcy. In fact, we are flying on free tickets for our cruise at Thanksgiving, so that says something...You may have to connect, which you are likely not used to from PIT but which for me is a fact of flying anywhere beyond the hubs.
2. PIT has been hit hard by the cutbacks, but if the airline begins to recover, I think that you'll see flights added back from/to there.
3. IMHO, I think that except for trying to book an award ticket which does require you to commit this far ahead, you are booking too soon. Your flights will get changed a bunch of times (see all the threads on this topic on these boards) and you are giving the airline your money to hold for close to a year. Given that none of the US majors are in good financial health, I don't want them holding my money! You will do as well to book anywhere from 90-120 days out, or even sooner.
If you want the real deal on any airline from a FF perspective, check out the boards at flyertalk.com.
I hope this helps you.