This is all pretty puzzling to me. My understanding was that we wouldn't see any new Airtran service. Although the international routes may make sense until the operating certificates are merged, the domestic flights are strange.
The only way to make sense is from a 717 utilization standpoint, along with an interline or codeshare agreement long before these routes take off. Right now, you couldn't even get FF benefits between the two.
strange stuff, but F9 had better be afraid either way.