Potentially interesting Republican candidate: Chrysovalantis Kefalas. He's a former aide to both US AG Eric Holder (D) and Governor Ehrlich.
Currently, he's the VP of Executive Communications at the National Association of Manufacturers.
He's gay, and he signed onto Project Rightside’s amicus brief in support of the freedom to marry.
Pity, but no chances in conservative Republican primary. As i said many times - i consider former Senator Charles Mathias to be my political "mentor", but after Morella i don't see moderate Republicans with good chances anymore in Maryland... Those, that exist, are simply unable to win primaries..