It's confirmed that Virgin America has the last four; their strategy from perimeter-limited LGA & DCA remains a head-scratcher. Southwest won 28 but gave back one Sunday-only flight pair, hence the strange 27 figure. I'm not sure what use anyone else has for a Sunday-only flight.

Some vague hints were dropped this week that WN & B6 will add flights to their network cities, and add a few frequencies to cities already served from DCA:
http://www.flightglobal.com/news/art...s-from-396268/
Southwest says MDW would be "logical," and B6 says that they'll fly to someplace north of FLL -- which is just about everywhere, but does include focus city MCO.