Having a homecooked meal from someone nearby? Sounds totally spot on. It could be quick if I want to leave (could be some social issues), WAY cheaper than delivery, cheaper even than eating out, and presumably it'll be healthier than just drinking tea and alcohol instead of eating (my usual diet).
That said, critical mass if the big challenge here - sites like this take a huge amount of focused effort. Feet-on-the-ground city-specific events, marketing, networking, etc. And mealmogul could face an even bigger challenge for people like me who live in SF without a car, but up on Twin Peaks with few people around.
That said, I'd love to be eating home cooked meals from my neighbors soon, so I hope they can find a way to explode in SF!