My company develops several types of applications. A lot of our business comes from doing multimedia-type apps, typically done in Flash. However, now that side of the hous
Silverlight programmer's don't know what they're missing out on, when it comes to Flex. Silverlight lacks the component model and event triggering capabilites that Flex has. Using XNA, and C#, a friend of mine has to jump through all kinds of hoops to get his Silverlight application to work. Then, it has to be handed off to a designer to get it to look half way decent.
Listen to the deepfriedbytes.com podcasts on Silverlight, and you'll hear how even a couple guys that really push Silverlight, acknowledge some of these issues. (I think, if I recall correctly, one of the guys works for Microsoft, but I could be wrong - I listened to it last week). They agree that Silverlight isn't quite ready for any huge applications, in its current state.
I would go with Flex, for a nice clean, straightforward approach - especially if you're already familiar with Flash and ActionScript 3.0. Flex makes alot more sense, in my opinion - Silverlight still has to mature.