Microsoft officials shared details about the latest promotion on July 2 on the Windows Team blog.
That's substantially cheaper than Microsoft traditionally charges for "upgrade" versions of Windows. With Windows 7, Microsoft charged users roughly $119 to $219 (estimated retail prices) to upgrde from comparable versions of Vista to 7.
The coming offer, available through Windows.com, is good in 131 markets, according to today's blog post. Windows Media Center can be added for free to this bundle through the "add features" option after the upgrade. (Microsoft officials have said previously that Windows Media Center would be a low-priced add on to Windows 8 Pro.)
Those purchasing the Windows 8 Pro upgrade through Windows.com also will have the option of purchasing a backup DVD for $15 plus shipping and handling. Those preferring to buy from a local store will be able to purchase a packaged DVD version of the upgrade to Windows 8 Pro for $69.99 during this promotion period.
This upgrade promotion for Windows 8 Pro both online and at retail runs through January 31, 2013. It commences as of the general availability of Windows 8, confirmed a tweet from a Microsoft public relations rep.
Microsoft officials announced recently another Windows 8 upgrade promotion -- the $14.99 Windows 8 Upgrade offer available to those purchasing new Windows 7 PCs between June 2, 2012 and January 31, 2013.
Microsoft officials also disclosed officially the supported upgrade paths for Windows 8 in a fairly general way in today's post (thanks @TheRackow). I posted late last week more complete information that has been shared privately with select individuals about the upgrade options available to XP, Vista and Windows 7 users for Windows 8.
Microsoft officials have not said publicly when Windows 8, in its four or so various flavors, will be generally available. The latest rumored release-to-manufacturing dates for Windows 8 are now centering around July 2012, with the rumored general-availability date expected by many to be in October 2012.
Update: By the way, upgrades are not the main way most users get the latest version of Windows. Far from it. Most -- both consumers and business users -- tend to wait until they are getting new PCs preloaded with a new version of Windows, rather than take the time and trouble to upgrade their existing PCs.
Update No. 2 (July 5): Computerworld (citing Microsoft as its source) says that users running the Windows 8 Release Preview also will be allowed to move to the Windows 8 Pro final version for $39.99 once the OS is generally available. Only personal data files will be kept, however; no settings or applications will be automatically moved over as part of the process, Computerworld added.