Allen Denver posted a note in his blog to let us know the VSSDK 2005 August CTP is now available. Here's a link:
Visual Studio Partner Programs Downloads
The August SDK adds 2 C# samples ( Package, MenusAndCommands ) that have been rewritten to our new quality level. It will work only with Visual Studio Beta2. This is unsupported and its not recommended to install this version of the SDK onto your main production machine - use with caution. We welcome your feedback through the extensibility newsgroups.