Yesterday I took a day trip over to DF to scout out the new terminal to help some exchange students that are coming to Puebla - I needed for them to be able to navigate from the new Terminal 2 to Terminal 1 to get to the airport bus terminal. While I was there, I talked a lot to the information folks about the status of T2. I also got a nice map of the inside, which I hadn't seen posted before.
I'll post the detailed guide later in this thread, but for arrivals who want to go to T1, the basic flow is exit customs, turn right, go up the escalator, keep straight until you run out of walkway, turn right and follow the little train/T1 signs (the train is not very well marked). You will need either a ticket, boarding pass, or e-ticket receipt to board the train. The train arrives at Terminal 1 between Puerta 6 and Puerta 5 on a station on the 3rd/4th floor of the parking deck. Once you leave the train and exit the train facility, turn left to walk across the bridge over the traffic below, then left again - then keep straight on the second floor until you see the Krispy Kreme on your left - at that point turn left and walk back across the traffic to arrive at the bus terminal.
If you don't have a ticket and want to get to/from T2, there is a 15-passenger shuttle bus that runs approx every 30 min between the two - it leaves from right in front of Puerta 6 on the ground floor. The AeroTren runs from 5AM-10PM, so if you are on the late Delta flight from Orlando like my wife was, you will have wait to take the along with the rest of your planes passengers (this can take awhile).
They were working on the T2 bus terminal while I was there, and one of the workers said that while they were almost done with the construction, the only client he had heard of that will initially have service is Caminante (to Toluca i'm guessing). He made it sound like the other bus lines haven't shown interest.

