http://finance.yahoo.com/news/americ...003453922.html
Apparently its at least US Airways, jetBlue, Alaska, Frontier, and Virgin America. Looks like US is the front runner with the unions in agreement already. jetBlue, possibly, with fleet commonality and its agreements with AA already. Alaska, doubt it as it seems they like being a stand alone. Frontier, maybe as Republic does want to unload Frontier. Virgin America, that's surprising.