I played weeknight Ponce de Leon as recent as last fall. There's a good number of options for adult baseball in the DC area. Ponce de Leon, DC MSBL/MABL, NABA (are they still around), and if you are real good, there's still the "Industrial League."
I thought the NoVA NABA folded up and the teams joined the DCMSBL. I played in the NoVA while I was there as well as the VBL and the DCMSBL but that was 1999-2001. I really liked the NABA because that was an all wood bat league and there were less teams which made for fewer forfeits.
What's the "Ponce de Leon?"
(And yes, terp, I know he was a Spanish explorer looking for the Fountain of Youth - that's not what I meant.