Silverlight v2.0 is getting closer and closer to RTM but I have yet to hear any stats as to how many browsers are running Silverlight. If I ask Adobe (by googling \"Flash in
Quick Answer: www.riastats.com
This site compares the different RIA plugins using graphical charts and graphs.
It gets its data from small snippets of javascripts running on sites accross the web (approx 400,000 last time I looked)
At the time of this post, Silverlight 2 was sitting at close to 11%.
I would not take this as the end-all, be-all in RIA stats, but it's the best site I've found so far.