As of today the Community Technical Preview of "WPF/E" (codename) is available to download.
Take a peek here: http://msdn.microsoft.com/wpfe
It's available for Safari on the MAC, and FireFox for Windows as well as Internet Explorer for Windows.
You can see some great samples at: https://channel9.msdn.com/playground/wpfe/
A getting started screencast: https://channel9.msdn.com/Showpost.aspx?postid=263365
It's associated whitepaper: http://msdn2.microsoft.com/en-us/library/bb190632.aspx
Have fun! I'll update more on this blog as well as going through some programming samples in the coming days!