It would be a nice touch to be able to pick a weather forecast service, not that I have anything against accuweather, but my personal favourite yr.no is amazingly accurate and I'm sure other people have their preferences too
I would like to be able to switch weather providers too. I personally want to use NWS/NOAA data, and Japan Meteorological Agency when I am in the region. I like to use public/non-commercialized weather data, and going directly to the website is great, but it would be even better if their data was available in the Firefox Home page on the weather widget.