I think he's basically got the right idea and encouraging adults to learn to cook is going to do a hell of a lot more to tackle obesity and general health in this country than improving school dinners. Not that I don't think they need improving, but they're just 5 meals out of about 21 a week, so quite a small proportion of a child's food.
What I think needs to happen is for the government to set up free cooking classes for adults in the evenings, teaching how to cook a dozen cheap, healthy meals with tips on how to buy ingredients cheaply and setting out the cost of making them so people can see just how much money they can save. I'd aim them at parents with young children and provide a creche if necessary.
I liked Jamie's idea of getting people enthusiastic and telling their friends and I would get these sort of people to act as paid 'mentors' at these cooking classes so people are getting encouragement from their peers and not just an outside teacher/tutor who they don't know.
I don't think the government is far-sighted enough to cough up the money for this sort of scheme though, which is a shame because diet-related health problems are costing this country a fortune.