The folks at Readify.com have formed a mailing list titled "OzSilverlight". It's something in which I'll obviously be heavily involved if as life in the realms of Silverlight continue.
It's gotten off to a great initial start and if you want access to it, then simply flick an email to:
email@example.com?subject=subscribe with the subject "subscribe"
I love this kind of community grass roots creativity.