Changing my question posted 5/9/11. I found in Rick's s that there is now a bus from Atoch to the airport with what looks like one stop. Can' find a bus schedule that suggests how long that takes. Anyone ever ride that route?
Yes, I took it in late February. Here's the schedule: http://www.emtmadrid.es/lineaAeropuerto/horarios.html Costs 2 euros. I arrived on a Sunday morning, so it took less than 40 minutes from MAD to Atocha. So much better than the subway!! WOW!
We rode the airport bus today. Went to T4, which is the last stop. It took the expected 40 minutes and was trouble-free. Among the best 2 euros we ever spent.