What a scary topic that could get generalized out of this world... That's why I clicked it 😀
But I'll put it this way. "smart" or "intelligent" for using a Mac aside, I think there is a different aspect. My generation, the college age, has a disturbing lack of common sense, or the will to acquire common sense. The attitude of "whatever" or "it's beyond me" is far too wide spread, partially because there is so much to know these days (but that is a whole other topic).
However, what being a Mac user generally shows is that someone was willing to go out of their way to understand a topic for which they aren't forced into. Their own research and understanding was required, and this, at least to me, is a very attractive quality in a female.
Now of course there are other reasons for owning a Mac (you're easily persuaded), which is probably why I've never really been attracted to a Mac user. However those girls always get me to investigate who they are 😉
~Tyler
I'm also a CS major, so take that into account 😉