Awesome news today that will please many (Thargy?) is that Rx is now open source.The new home page has just gone up

http://rx.codeplex.com/

Scott Hanselman himself is plugging it

http://www.hanselman.com/blog/ReactiveExtensionsRxIsNowOpenSource.aspx

And we even get a mention for the IntroToRx.com site (Yay!)