Spirit Airlines switched CEO's last week. They haven't been running a good operation or growing outside the south and east much, but that still puts them in the top tier or US airlines. They brought in the former CEO of AirTran (nee Value Jet) who lead them through their sale to Southwest. This got bloggers talking about Spirit and Frontier merging. I think a merger isn't the goal because AirTran ran a solid operation and Spirit needs help there most.