Wow. How many things are there out there like this, where you just vaguely assume that someone's already doing it - that weather companies are all data-crazy and keep every last byte and analyse it seven ways to Sunday and sell it in every way they can - and it turns out no-one was doing any such thing until this guy thought he'd write a Python script?
There's a reason I have two weather apps on my (shiny new) BlackBerry.
But yes - there are endless startup opportunities for the next Nate Silver.
Eric Floehr has a business that "holds a mirror up" to weather forecasters, and aggregates and evaluates forecasters for weather forecast consumers. Rationalists interested in improving our societies truth orientation might be mildly interested.
http://www.johndcook.com/blog/2011/04/12/weather-forecast-accuracy/