Cute, but think twice about making this the focus of your time as people have advised above. Finding a cofounder is a pain point for many people (myself included) but the market can't be very large. You will also have to address a challenge that regular dating sites have, namely that those who successfully find a match will no longer use your service. Unlike regular dating sites, cofounder-matching sites seem stacked with people looking for help with their idea, perhaps because those willing to work for someone else already have a job and aren't as driven to get involved. Are there really an equal number of people who think "I'd love to work on a startup but don't have an idea of my own that I am passionate about"?

That being said, none of the cofounder-matching sites I've used have solved my problem so I suppose there is room in this space. If you did take a cue from OKC and institute a system of curated user-generated Q&As you might be on to something. The services I've used were primitive in their matching ability (e.g. I am a developer looking for a designer, which tells you nothing about values, principles, working style, etc.) so hey, maybe you could make it work.