As nybiker says, DC is great for riding for transportation. I'm no longer familiar with the racing scene since I moved 100 miles south, but there are high end bike shops in DC (Revolution comes to mind) and Maryland that will likely have racing info.

I lived in DC, Virgina and Maryland during my time in the DC area. I liked them all. One thing to consider is the income tax--it was a lot higher in DC than in either MD or VA. when I moved out of DC, my paycheck went up a pretty nice chunk. But I also really enjoyed living in the District itself and would have stayed if I could have afforded to. It's very expensive to live there (the whole region, not just DC).

Congratulations on your move.