Heh, I mentioned "original Star Trek in general" because I didn't want to suggest that Khan is associated with the whole umbrella brand.
Call it Kirk/Spock Trek, if it makes any difference. What the general public see Star Trek as, ie) not Voyager or DS9 or anything.
My point is that Khan isn't as big a deal as you suggest, certainly not to the same degree as the Joker is to Batman.
He may not be "Joker" big (which was helped by a certain actor's death,) but he is a big deal in the realm of Sci Fi, and needless to say Star Trek. Take at various rankings from the media regarding Star Trek/Sci Villains
http://www.msnbc.msn.com/id/30505683/ (Also take note of the voters poll)
http://stars.ign.com/articles/977/977989p5.html
http://blogs.ign.com/SCI-FI-BRAIN/2006/06/29/23252/
http://trekweb.com/articles/2009/11...ounces-Winner-of-Best-Star-Trek-Villain.shtml
Needless to say... Khan is no "small beans."