According to the latest seniority list Seniority #600 would be around late June 2007 hire.

I don't know where you guys are getting this merger between Comair and Mesaba rumor, but it is just that. Only thing I've heard is that merger between Comair and Mesaba is highly unlikely, and that if any merger does happen it would be between Compass and Mesaba. However, I can't see that happening because that is not how DAL operates. DAL management has been saying the number of DCI carriers flying for DAL will be reduced down from 8 to around 4 or 5, but I do not expect DAL to merge Comair and Mesaba. Too much headache for the DAL management in merging two airlines with a large number of very senior pilots at the top. Besides, DAL will probably keep Mesaba, Compass and Comair separate to keep the option to sell off either Mesaba or Compass individually to make profit.