If you do a google search, you'll find plenty of old references to it and screenshots showing where it should be, but in 2.0.2 on both my vista and windows 7 computers, it's just not there. (Even when showing "all" settings.)
And it's the only way to easily UNSET a hotkey, rather than just CHANGE it.
Sup with that?
Well, actually, now I'm experimenting I find I can change it to SAY "Unset" if I try to set it to something like num lock or pause break.
So I'll post this so future people with this question may find that.
And also to say that maybe there should be a little note explaining it in preferences?