One of the big themes of MIX is Silverlight. Silverlight allows developers and designers to release applications and content with extremely rich user experiences in a web browser.

I knew Silverlight was going to be big, but the quality of the demos shown still amazed me. Cross-platform debugging. Running .NET code within a browser - even in Firefox or on a Mac. Dynamic language support, including ruby. Amazing. Check it out: http://silverlight.net.