Although the public beta for Windows 7 beta will only available on January 9, 2009, the MSDN and Technet subscribers can now start downloading the DVD ISO media together with a genuine working product key to activate the Windows 7 installed.
The details of the DVD ISO image available for download form MSDN and Technet are:
Windows 7 Beta (x64) - DVD (English)
File Name: en_windows_7_beta_dvd_x64_x15-29074.iso
Date Posted (UTC): 12/30/2008 4:26:48 PM
SHA1: E09FDBC1CB3A92CF6CC872040FDAF65553AB62A5
ISO/CRC: 8E2FAD39
Windows 7 Beta (x86) - DVD (English)
File Name: en_windows_7_beta_dvd_x86_x15-29073.iso
Date Posted (UTC): 12/22/2008 2:41:15 PM
SHA1: 6071184282B2156FF61CDC5260545C078CCA31EE
ISO/CRC: AABA5A48