Yes, this new foot traffic pattern is a mess. I have been in one Friday PM crunch and one Monday AM crunch, with the following experiences:
1. If they force you back along the ticket counters before entering the security lines, you can bear right, even going past the rope barriers, and enter the South terminal elite line. My own opinion is that it is still shorter than the main lines during peak periods.
2. In both recent jam-ups, both elite lines on the North Side (main and T-gates) were CLOSED or, worse, had been OPENED TO ALL travellers. Last Friday I had luck going all the way around the lobby on foot, joining the South Terminal line, and using my new AirTran elite credentials along with the Delta folks. They didn't bat an eye, but I don't know yet if that is officially "OK."
A TSA employee said they were short 150 staff in Atlanta!