Believe me, if ANY major airline was actually hiring flight attendants, it would be big, big news... it would also be extremely competitive.
As far as I know Continental Express F/As do not have flow-through rights. I dont think there is any US carrier that lets commuter F/As flow through to the actual airline. US Airways MidAtlantic division will employ furloughed mainline flight attendants who will of course return to mainline when they can. After the list of willing furloughees has been gone through, they will hire off the street but those F/As will be qualified for MAA aircraft only and will not flow to US Airways.
Not sure about the other airlines, but I've not heard of it. CoEx was spun off in an IPO as ExpressJet and isnt as connected to CO as they were.