Wilson's use of "someone" may be even more profound than you give it credit for. His unwillingness to use gendered pronouns in his speech indicates not only that the gender might be male, but that he's trying not to lie. It has been my experience that when you have an overwhelming secret, such as being gay, you have to let it leak out or you go mad. It becomes impossible to say straight out that you love him/her if that's a lie, but rather than give the true gender you protect yourself by using neutral pronouns. You reason with yourself by saying, "It's alright, I told them, they would know if they looked a little closer. It's not my fault they never do." In addition, there is an immense internal pressure to not betray yourself, to not conform any more than you have to to escape outside retribution.

How does this indicate that Wilson is gay and not merely that he fell in love with a man? Because he wouldn't feel so threatened if he were confident in his heterosexuality. Cameron is a relatively passive individual who poses no threat to Wilson, so revealing to her that he had once been in love with a man should not be so difficult. He would not have had to name names, to that takes out the possibile awkward factor of his affections being for House (or anyone else she knows, for that matter). With those factors out of the way, we're left with someone who still hasn't accepted that he likes men and as a result is stuck denying and asserting himself at the same time.

Wilson's vagueness, therefore, indicates more than that the object of his affections is male - it also shows that he is going through the same half-assed cover-ups I've seens GLBT people go through, and have gone through myself. He's not just attracted to one man - he's attracted to men.