Thanks Mark for this one. The pre-registration for the public betas of Windows Vista, Office 2007, and Exhange Server 2007 is now online.

Lead evaluations for new technologies and understand their impact on your IT environment and their potential for your company by pre-registering here. You will be notified first when the Windows Vista, Office 2007 and Exchange Server 2007 public beta releases become available. Additionally, you will receive updates and information regularly through the Microsoft TechNet Flash Newsletter, from the time you pre-register until the launch of the product.

Technet Pre-Beta Release Registration