I had the same stance as you until Season 3 rolled around, when TPTB started writing Wilson in a way that his behavior reminded me of closeted gay men I've come across in real life.

But the point wasn't "Wilson is definitely gay," but rather, "Wilson can easily be written as gay." Because, well, he could. And that's what ultimately matters.

Wilson is not gay.

I don't believe in the "straight until proven otherwise" stance when it comes to fictional characters, so, to me, no one can definitively say what Wilson's orientation is (and in my opinion, the evidence that he is more than occasionally attracted to women is feeble).

Wilson is in love with House.

This is something that anyone with eyes and half a brain should be able to see - his behavior screams love so loudly that even casual viewers seem to pick up on it =)