Same question here, if someone could post a link to the current 'participating airlines' for resort check in, we could just keep checking there for new airlines. Many people are flying Southwest, and I will probably be flying Alaska. We wouldn't have to keep searching like this on the DIS if we knew how to get the info straight from Disney.
I don't know why it's been so hard to find!
The idea of checking in at the resort instead of the airport may make a difference in what airline I choose.
Also, Southwest and Alaska partner with Disney in promotions all the time, that's why I think they may join the party here.