I initially started researching Silverlight with the goal of using IronPython (eventually IronRuby) as a language of choice to develop rich client applications, but came to the conclusion that Silverlight is much less than just a watered down WPF. There are no input controls, and unless you’re willing to invest the time to create your own ComboBoxes, Checkboxes, etc. it’s not worth the effort. Adobe Appollo is looking much more promising each day, unless Microsoft figures out a way to make WPF cross-platform. My idealistic goal would be able to develop cross-platform applications in Python or Ruby that can be installed to Windows or Macs (even Linux). One good thing about Silverlight is that the streaming video quality looks fantastic.