Really, for all of you who insist on using the feeble excuse that "He's gay" - that's pretty pathetic. For you to take the scenes where Naruto & Sasuke have ended up kissing (which have always been by accident merely done for the use of comic relief on Kishimoto's part) and then come to such a conclusion is pretty shallow. I'm sure if that was Kishimoto's real intention there'd be a lot more romance involved in the series than there currently is, so cut it out.
julio10ification:
It's a pleasant theory, but a female 'Uchiha' would mean that for them to get together would be incest, so it'd have to be someone outside of his clan; from what I've seen in the anime there have been no female Uchiha's, which further strengthens my point. In either case, I don't think Kishimoto has that sort of end in mind for Sasuke, so because of 'Plot no Jutsu', I doubt such a thing would ever transpire.