It seems like an official download link to a web installer for WinFX SDK Beta 1 RC 1 has been leaked. Some people already have it now, and others are downloading it. I personally haven’t heard (yet) when Release Candidate 1 of Beta 1 should have been released officially, but I’m sure it’ll be soon.

Edit: I got ahold of the release — it’s just contains the Avalon bits — 6.0.5062.0 (vbl_wcp_avalon(yungt).050429-0931), and Indigo. IMO, the release overall is disappointing - the SDK is not included, no new syntax schema, either (this one is because I use the released Schemas for my Xaml Editor application ).