I've seen plenty of niche/vertical opportunities like this - mainly because I enjoy interrogating people who work in various sectors about their jobs and pain points.
These opportunities will not be on the radar of someone who doesn't have in depth knowledge of the sector in question. For us, the key was personal experience and knowing potential customers. We worked with them to build the product from the beginning.
As the article says, it's about having a team with complementary skills. That's often a product guy (either a business person or just someone who knows the sector really well) and some tech guys.
You see business guy founder's companies regularly on techcrunch, how often do you bother to look into the background of founders on news stories ?
Arrington is the sole founder, and his "startup" was just a wordpress install.
Anne Wojcicki doesn't have a programmer co founder.
Guy Kawasaki paid thousands to build alltop, so doesn't apply.
Seth Godin is a marketer/blogger, so once again, no technical cofounder.
Kawasaki co-founded (and sold) Fog City Software with programmer cofounders.
Godin has founded a number of startups including with programmers I believe.
I just don't buy that. Looking for a programmer partner as a biz guy with just an idea, is the equivalent of looking for VC funding with an idea...it might happen, but chances are it's a huge waste of time.