Beta testers started receiving invites from Microsoft last Friday for joining the Longhorn Beta program. These invites are expected to continue arriving for the next few days to all selected testers.

Microsoft has released a flood of e-mails to people inviting them to login to and enter an invite id to sign up to beta test Windows codename 'Longhorn'.
No date has been set for the final release of Longhorn, although after some feature cutback, the OS platform is expected to be 'done' by late 2006, or early 2007.