A quick email arrived late in the day:
Subject: How the Gawker Stole Gay Christmas.
Ok. I hate to break it to you but Gawker used the word "gay christmas" today. But just look at it like this. Its like star and people fighting over who invented "bennifer."
But Offender lays no claim of ownership of Gay Christmas. Yes, Gawker used 'Gay Christmas' today, but so have Modern Fabulosity and Bourgeois Nerd, as well as this site down in Virginia. Hugh Voltage brought California to the house of Gay Christmas and Hayden used it while fretting over costumery this weekend.
In fact, the term predates my original posting from such diverse sources as The Butch Stroll, The Soup, pridenation, Jason's Room, and even a livejournal post mentions it.
Conclusion? Gay Christmas is for everybody. Gay Christmas is everywhere.