The official Orcas RTM OM documentation was posted a while ago, and I neglected to blog about it!  It's available here: http://www.microsoft.com/downloads/details.aspx?FamilyID=6466b53d-d80b-4c31-8f5c-dfb5d32e9411&DisplayLang=en. 

Make sure to follow the instructions for viewing it after downloading:

Method 1

  1. Double-click the .chm file.
  2. In the Open File-Security Warning dialog box, clear the Always ask before opening this file check box.
  3. Click Open.
Method 2
  1. Right-click the CHM file, and then click Properties.
  2. Click Unblock.
  3. Double-click the .chm file to open the file.

I'm yanking the Beta 2 documentation now that this has been posted...