This was a little bit of a shock but it leads me to think of a few things.

Without knowing how they are moving tails around the system, it seems they can't place the "Frontier" aircraft with another carrier. 10% is a big number which also leads me to believe that the future deliveries may also be in jeopardy or are already under negotiations to be cancelled. Only time will tell how this pans out.

BB terminated the SAAB probationary pilots after 9/11 because they weren't needed. You could have been online a month on the jet and safe, but if you were on the SAAB in your 11 month you could have been gone with no recall rights. With the different fleet types, if RAH determines it would cost more money to retrain a bunch of people with a furghlough than fire them, they would probably lean towards firing. I don't know the details but it looks like even AirTran may be firing the probabtionary pilots there.