In case you haven't heard, DC has voted 12-1 to recognize same-sex marriages performed in other states. (My favorite part of this is the ministers yelling, "get them off the council" about every member of the DC council except Marion Barry.) This is actually huge, because it means that either people from DC can go to states and get married and come home and be married, or it means that people who are married in other states don't need to worry about no longer being married when they move to DC. This will also have an effect on diplomats from other countries where gay marriage is legal who move to DC, because their marriage will be recognized there. (I'm actually fuzzy on the law for how we deal with international gay marriage.)
I still can't believe that DOMA is allowed to override the full faith and credit clause, but don't even get me started.
I think that laws like this (NY judges recently ruled the same thing - that New York had to give credence to gay marriages from other states) are an important step for gay rights, because they make people a little bit more comfortable than gay marriage, but it has a lot of meaning for the people they affect. I think that it is significantly more likely that Maryland will pass a law like this than a law supporting gay marriage anytime soon (and in the Fall of '07, the courts said that the MD Equal Protection clause is not violated by not allowing gay couples to marry).
The DC law has to be passed by Mayor Adrian Fenty and then put before Congress for Congressional review. I do not know how that will go - but I will be furious if Congress tells DC that they can't pass this law without a legitimate legal argument.
I think that for states to not have to recognize things like marriages performed in other states goes against the entire point of having a United States. Can you imagine how devastated you would be if being married in Maryland meant you had to stay in Maryland because that was the only place your marriage was valid?