Having read about security in ORD I asked at Frist Class check-in if there was priority security. The agent replied there was and asked if I wanted to be shown the way. I'm glad I accepted the offer because the agent actually took me to the front of the priority queue using her badge and made sure I was in the correct security line.

When boarding was called (far too early I thought) there was no escort but I just followed a couple of guys who seemed to know what they were doing and went through the (unmarked) priority boarding gate.