I have a few things to add to this.
Know something I don't. Plenty of people seem to operate under a false dichotomy between code and business, where "not programming" gets treated as a business skill. I consider myself a hybrid hacker/businessman, but stronger on the hacker side for now. If I am to take a "business person" as a partner, I'm looking for that person to do things I couldn't learn easily from a day of reading. This could mean lots of things: truly understanding markets and pricing, being a professional member of a specialized target market, legal and accounting training, unlimited patience for customer support, etc.
I see some "business" people making the same mistakes they're supposed to prevent. The stereotype is of a programmer who builds and builds without testing the market, but how many non-programmers try to recruit techs to hack together a totally untested but "revolutionary" idea?
Another thing I've gotten wiser to is the use of vague terms, like "leadership" and "networking." To me this comes off as "I wanna be the boss and hang out." If you really are good at these things, try to give some specifics.
Finally, if I wanted to have a boss and live in a hole, I'd get a job at X big corporation. This is the point I expect the most disagreement on. I don't want a business founder who will "take over" all of the networking. By deciding to be a founder, I've already bet that I can manage myself better than someone else can manage me.