Looks like Novell (MS) released an Open Source version of the Silverlight plug-in for Linux named Moonlight.

The goals according to the site are:

• To run Silverlight applications on Linux.
• To provide a Linux SDK to build Silverlight applications.
• To reuse the Silverlight engine we have built for desktop applications.”

Interesting they’ve come across some of the same problems of Flash player with their version of ‘window mode’ on Firefox. I do like the Known Issues from the project page:
Especiall this one “Microsoft’s Silverlight plug-in is installed but it doesn’t do anything”

It just partially funny really. I applaud them for having this be open source so users can create their own version of Silverlight Players, yet this particular version completely lacks most if not all multimedia playback. But I’m sure it will soon so I’ll be keeping my eye one it.