Pick up your jaw and get over it already, World.
The only reason I find it interesting at all is because of the 'love is blind' slant it puts on the Grindelwald episode ~ partly why Dumbledore didn't see Grindelwald for what he really was.
I did find this anecdote from JKR cute:
...recently I was in a script read through for the sixth film, and they had Dumbledore saying a line to Harry early in the script saying I knew a girl once, whose hair... [laughter]. I had to write a little note in the margin and slide it along to the scriptwriter, "Dumbledore's gay!"