Doctor Who "You're so gay" controversy

Update: Yes, this did happen a few years back. I was tipped off by someone to it (coughMICHAEL!cough) and assumed that the ep had aired here in the States recently, which isn't even the case. So yeah, it's old and I air-balled this one -- sorry! But it's still an interesting topic that had never been discussed here on the site and one that is still an issue (with Knocked Up, etc).

A minor controversy has bubbled up recently a long time ago over the use of the word "gay" to mean -- well, it's not entirely clear what it was supposed to mean -- on the cult fan-fave Doctor Who series.

According to Nicklas Johnson, who has been charting both sides of the fan response to the word's use, this is how things started:

About 5 minutes and 25 seconds into Aliens of London, we were presented with this exchange between the Doctor and Rose atop an apartment building in London:

Rose: she slapped you!
Doctor: 900 years of time and space and I've never been slapped by someone's mother.
Rose: your face...
Doctor: It hurt!!
Rose: You're so gay!

Now mind you, Doctor Who has a massive gay fan base and the writer and executive producer Russell T Davies is himself gay. So it's hard to believe that Russell intended this remark as some sort of affront to gays.

This kind of reminds me of when The Maltese Falcon was adapted for the screen and the way that they decided to communicate to the audience that Peter Lorre's character was gay was to have him slapped by another man (apparently, you slap a woman or a gay guy and punch a man -- write this down, folks, it will be on the test). But I don't think that's the point here.

Fan response has been across the board, from those who feel it's offensive to those who feel that it's simply the way people talk, and everything in between. Davies himself has said that the word gay is constantly evolving, arguing, "It seems to me that we're becoming people who complain about the use of the word gay, much as people *used* to complain about the word gay, because it no longer meant 'happy'. No words stay static."

Interesting, though not entirely convincing or relevant, argument. What do you think? Is "gay" an insult? Or is it more insulting when negative reactions imply that it should be?