When I flew home from FL in January 09, CBR was not particpating in Southwest check in at the resort. But we were able to go to Guest Services at the park we went to that morning (MK I think), and they checked us in online. We were there like 24hrs 5min before our flight, and the awesome guest service lady got us A18 and A19!
So if your resort is not doing Southwest checking, definitely check with Guest Services in the parks!!