I think this is very, very cool.
Anyone who's spent any time in a virtual world knows that in-game 'romantic' relationships are as common as tails on squirrels. As a moderator for a teen-centric site, there are all sorts of aspects of these relationships that concern me greatly. In most cases, it doesn't matter what I think.
Its also concerns me that we have to ban the words "gay" and "lesbian" from the ourWorld chat because we don't trust our players enough to use the words in a positive light. Even a quick review of the chat logs shows that our fears are well founded. Both "gay"and "lesbian" are used almost exclusively as insults, thrown around with disturbing regularity (While technically filtered, it's easy to misspell a word radically enough to defeat any filter: ghey, g4y, qay, ga7, etc.)
For a game to look past all that and officially sanction same sex marriage is very, very cool to me. It shows that while many players haven't grown up regarding sexual preference, at least one game company has.