Winner!

Recently had to decide between Silverlight vs Flash for a project.

Silverlight pros:

* Fast.
* 2.0 would support IronRuby
* Easy
* Already have development tools

Flash & Flex pros:

* Installed everywhere.
* Tons of resources
* Lots of preexisting stuff I can look at.
* Similar to JavaScript

Since I already had the MS tools and Flex builder would have cost me some extra change, I was leaning to Silverlight -- until I found out it doesn't support Webcam / Audio!

When deciding on which major technology to use, always determine that all prospective contenders support your required features!