Customer service and ramp workers from Comair, Mesaba, and Compass (the latter two acquired via the Northwest merger) will be put into one company unimaginatively called Regional Handling Services. The other parts of those airlines will continue to operate separately, but you have to wonder if this is a precursor to more consolidation.
Delta has long had contracts with more regional carriers than one would think humanly possible, but the addition of Northwest and its contract carriers pushed this to the level of absurdity. You can now find Delta putting their name on planes operated by Comair, Atlantic Southeast, SkyWest, Pinnacle, Freedom, Chautauqua, Shuttle America, Mesaba, and Compass. With three of those being wholly-owned, you would think that some consolidation would be worthwhile.
Not only will they be able to gain some efficiencies on the management side, but more importantly they'll be able to give more consistency to those passengers who deal with these employees when they fly. Having one company with one set of policies should be able to give a bit more sanity to the airport environment, if it's done right.
There shouldn't be much overlap between these carriers except where Comair used to handle Delta flights and Mesaba or Compass handled Northwest flights. (I'm not even sure if such a station exists.) So job loss on the front line will be minimal. In return, it should help make things run more smoothly.