The Windows 7 Team published an update on the availability of the Windows 7 public beta
>> Update on Windows 7 Beta Availability
Due to very heavy traffic we’re seeing as a result of interest in the Windows 7 Beta, we are adding some additional infrastructure support to the Microsoft.com properties before we post the public beta. We want to ensure customers have the best possible experience when downloading the beta, and I’ll be posting here again soon once the beta goes live. Stay tuned! We are excited that you are excited!
>> Update on Windows 7 Beta Availability