Here's an interesting video
that gives you an idea of what working with data on the web can be like using Silverlight. The company is Data Applied, and if you can take the robotic narration you'll see some interesting data visualization examples. There's a link to sign up
and try crunching your own data for free. I tried it out with and it's definitely worth a look. One nit I have is the mouse wheel deepzooms the data rather than scrolls the list. But there are interesting analysis you can run, like pivots, tree maps, forecasts and correlations. If you're a data viz junkie, you'll find a lot to keep you busy.