I believe that Kali's Court and Mezze will be open. As Hon pointed out--since Christmas Eve falls on a Saturday, a lot of restaurants will be open. They will probably have abbreviated hours.
Last Christmas, which fell on a Saturday, we dined at the Prime Rib (not in Fells Point). They are open this Christmas Eve, but not Christmas Day.
Outside of Fells Point, I believe that McCormick and Schmick is open on Christmas Day. I took my Mom there about 8 years ago on a Christmas Day. Since it was just the two of us that year we didn't want to be home alone and that was just about the only place open. We didn't order the traditional turkey meal, but opted for seafood selections, which were okay at best.