Rusty Howell from Novell announced that they have released the next version of Moonlight. You can download the Firefox Plugin from this link and install it on your Linux box. If you are willing to get more closer with Moonlight, you can get the whole sourcecode from here or you can check-out from SVN.
svn co svn://anonsvn.mono-project.com/source/trunk/moon
What is Moonlight?
Moonlight is an open source implementation of Microsoft Silverlight for Unix systems. The official Microsoft Silverlight plugin doesn’t work on Linux or Unix systems so that Mono team developed Moonlight, an open source firefox plugin, for Linux users.
According to the bug list, there are currently 59 issues in this release. I hope those all will be resolved very soon. If you encounter any issue with that plugin, you can send it to the Moonlight team via this link. Enjoy!