I just followed one of the links to the MIX University to have a look at the Silverlight Firestarter, and came across this:

http://www.visitmix.com/University/silverlight/firestarter/


Take a particularly good look at the rollover on the right - I don't know what the hell it's doing, but they're obviously not doing it right. The rollover animation is sparodic and jumpy, and it wasn't even that great an idea to start off with.

You'll also notice on the left panel that the overlay highlighting doesn't follow the Z-index of the pictures correctly or smoothly.

A particularly bad example of Silverlight usage, and certainly not something that should be the frontpage advert for new Silverlight users.

Edit: It seems to work better in IE7 (but is still jumpy and ugly) - it's truly appalling in Firefox.