WPF or Silverlight??

Now that the stock quotes component is kind of usable (still have a few ideas, maybe another week or so, expect a new release), I thought I can use it to build a good portfolio tracker. I know there are a lot of those, some free, some paid, but none that is good and also free..:)

Anyway this is something I had in my mind for a long time, but never got around to doing it. Now I am kind of trying to decide on whether I go with WPF and a smart client approach or a Silverlight and a hosted approach.

I kind of like the hosted approach in that I can update the code etc and people can use it directly off the site etc. But then I am kind of disapointed with the kind of controls that are avbl and the early stages of the runtime itself. (obviously I will use only 1.1, as I am horrible at scripting, I can only write .NET code)

WPF seems more stable, but then people will have to download and install it locally. Apart from also having to have the runtime etc..

Any experiences? suggestions??