I think it is known by many, though perhaps not all, that the word most commonly translated as "overman" (or "superman" in older translations) is "uebermensch," not "ubermann." "Mensch" is German for "human being," not for "man." In translations of Kant, for example, it is almost always translated as "human being" (since Kant's writing is so stiff and pedantic, the rather stiff and pedantic air that sprinkling "human being" all over the discussion adds fits in perfectly in Kant's writing, while it would be a bit jarring in Nietzsche's smooth prose).
Little significance is usually attached to this, since "Mensch" is simply as a matter of German idiom much more commonly used than the English "human being," and Nietzsche's well-known misogyny no doubt leads most to conclude that he's merely following German idiom (or perhaps following the practice of German philosophical writing, which tends to use Kant's terminology).
However, I've been reading some of my German texts of Nietzsche, and I turned up something interesting. While Nietzsche almost always uses "Mensch" rather than "Mann" when talking about a generic person, I found an exception. In his discussion of the master morality in The Genealogy of Morals, at a couple of places (such as the end of section 5 of part I) he uses "Mann" in contexts where I would initially have expected "Mensch." He is describing the historical origins of the master morality, and specifically quite patriarchal societies (like Rome), so "Mann" seems not inappropriate, but normally he uses "Mensch" even when in fact the group under discussion is mostly or entirely male (the "higher men" in the end of Zarathustra, for example, would be higher human beings if Kantian translation practices were being followed).
Since Nietzsche is so meticulously careful with words, his choice of "Mann" on these occasions is presumably not accidental. He is presumably intending to draw attention to the patriarchal nature of the original master morality. But in describing his own ideal, he doesn't use "Mann." So is Nietzsche's ideal then perhaps not patriarchal?