Not that there's anything wrong with that!
But seriously, if that aspect of Dumbledore's character is of central importance to the author and her story, which it apparently is, then one has to wonder why it wasn't highlighted more conspicuously in the series itself. I don't recall the issue of homosexuality coming up (or out) at all in the books in any major way, so it seems a bit anticlimatic, to put it mildly, and politely, to reveal it now, ex post facto. I mean, the discovery by Harry that his mentor Dumbledore is gay could have been a powerful parallel plot line playing off against the wizards v. muggles theme, but Rowling and/or her publisher must have felt that it would be too controversial or would negatively impact the popularity of her books. Now that she's finished, she can point to various characters and say, "Oh, by the way, this one was actually gay the whole time, and you never knew it, ha-ha!" Actually, there are a lot of textual clues about Dumbledore's sexuality, hence the speculation among fans, but all the same the circumstances of the revelation bug me. Do writers have an obligation to reveal every aspect of their characters' lives? Obviously not. But this strikes me as a very questionable omission on Rowling's part.