It's far too early to buy anything for June 2011, DCA or no DCA.

The fare will probably drop substantially three months out or so. Even if it doesn't, other deals / sales to DCA will appear. A few weeks ago I sent my wife SEA-MCI-DCA-DEN-SEA on Frontier for $279ai. At that price, and with CO $150-$200 more expensive including an EWR transfer, we forget about status and miles.

On CO, and usually on the other remaining majors, BWI will always be cheaper than DCA.