OMG, HP. (Work has made me late for the wank. Damn you!)
While, Dumbledore being gay is cool on a number of levels, not the last of which is the fact how much everyone is freaking out about it, the quote that made me laugh the most from that interview is this one:
Q: In the Goblet of Fire Dumbledore said his brother was prosecuted for practicing inappropriate charms [JKR buries her head, to laughter] on a goat; what were the inappropriate charms he was practicing on that goat?
JKR: How old are you?
Eight.
JKR: I think that he was trying to make a goat that was easy to keep clean [laughter], curly horns. That's a joke that works on a couple of levels. I really like Aberforth and his goats. But you know Aberforth having this strange fondness for goats if you've read book seven, came in really useful to Harry, later on, because a goat, a stag, you know. If you're a stupid Death Eater, what's the difference. So, that is my answer to YOU.

Re: HP
She was asked at an interview if Dumbledore ever fell in love (don't ask, we're fans, we ask the strangest things *g*) and she just mentioned that in her head D was gay and that she told the director of the next movie the same thing when he wanted to put in a reference to a former love interest of D's.
It's something that I think is well supported in the books (his friendship with his later archnemesis certainly read like a huge crush to *me*) but of course anything that's in the books is up for interpretation by the reader. People are freaking out because they apparently saw this differently and can't seem to cope with the fact that the author might have different ideas about a character's non-plot-related backstory than they do.