Assuming the number of pilots is directly proportional to the number of airplanes, my math says that about 185 people would be furloughed, based on 28% of 661 pilots.
Like others have said though, no one has any real idea what's going to happen when those leases expire, so we'll just have to wait and see where the truth lies between the "we're all DOOMED!" position coming from IBT and the grumpy senior guys, and the "positioned for growth, sunshine and puppies for everyone!" position coming from QX management.