Quite possibly, it's not a major fetish or anything, but I've been reading about stuff like that in Issac Asimov novels since I was a kid. People falling in love with (and invariably having sex with) things like robots, aliens, etc... are all classic science fiction concepts and I have no problem with envisioning it or thinking it could potentially happen to me.
I think the problem with the idea on the internet is people get ridiculously wierd about it, like getting to the point where they only way they can become aroused or enjoy porn or whatever is if it involves a furry, or an alien, or a robot or whatever. Despite how it might sound, I'm fairly tolerant of such things, and can enjoy some of the artwork as intended, but I can't see how people can form an actual sexual identity around something that doesn't exist.
On a final note, while I have watched quite a bit of Anime (and been a much bigger fan in the past than I currently am for some reason), I think the subject matter has been handled best in books. I just haven't seen much visual media like games, movies, anime, or comics that have ever done it well. Aside from Asimov and some of his stuff, I think perhaps the best "Robot Romance" was probably the one with Sheen (which actually starts with sex and then develops from there) from Piers Anthony's "Adept" series.