I can do a veer (back). Here's some fodder for DCA-ers.
Some TSA folks I know from work think it's good for DCA. First of all, they say it's ambitious to ramp up all the new airports by year end 2012 but that it's a scalable model after what they have so far. And that the idea is to start with existing partners including AA. At DCA, the B concourse is square in the middle of the main (or new) building. But DL has 48 departures -vs- 31 for AA. He says add UA in B and its 43 departures and B looks like the logical candidate.
I wasn't aware UA was up and running yet; haven't flown them much since last fall, PX to 2013 but I don't recall getting an invite.