Nothing major (to me personally) lost from DCA. DCA - BTV is a big one for me so I'm glad to see that one is still there.
A little surprised to see Jacksonville NC, Fayetteville NC, and Pensacola FL, go away due to their proximity to military bases(and obviously DCA's proximity to the Pentagon). My guess is they're betting that after a few months of those routes not existing the Pentagon via the Senate / House will make sure that flight is restored either on AA/US or another airline. Can't see those from the military trekking out to IAD from the Pentagon to get on those flights
I'm also really glad to see a second DCA - LAX flight will be put in place of the DCA- SAN flight. One can only hope the timing for the new one will be better (early morning and a red-eye would be great)