The TSA has put out a security directive pertaining to Military Passengers. According to Security Directive 1544-01-10w Access to Sterile concourse for non-traveling individuals.
"Military Passenger" Family Members may be given a pass
1. To escort the military passenger to the gate
2. To meet a military passenger's inbound arrival at the gate.
After talking to TSA for clarification the family member can go to the airline that the military member is flying on and receive a pass to go to the gate. You will be required to have a pass and a photo ID to get pass the security checkpoint.
This is especially a wonderful change for the military personnel who are on leave from Afghanistan or Iraq. It will be a better Welcome Home for you to get off the airplane and see your family at the gate and being able to stay with the family longer before having to leave.
Always check for a USO at the airport for a comfortable place to wait for your flight.