From the Windows Vista blog:



“Today we’re announcing further detail on how Windows Anytime Upgrade works. 
Come 30 January, Windows Anytime Upgrade will allow customers to purchase and
download a digital key to upgrade to a more feature-rich edition of Windows
Vista.  The user will then complete the upgrade process by inserting the Windows
Vista DVD that came with their PC or with their retail purchase of Windows
Vista.  The program will be available in the US, Canada, Europe and Japan.

Manufacturer’s suggested retail prices (MSRP) to upgrade from a more basic
version of Windows Vista are:

• Home Basic –> Home Premium:  $79
• Home Basic –> Ultimate:  $199
• Home Premium –> Ultimate:  $159
• Business –> Ultimate:  $139″