Windows 7 upgrades half price for a few days only!
You can pre-order Windows 7 starting Friday, June 26, 2009 at midnight eastern time and get at least half off. The offer is good until supplies run out or July 11, 2009, whichever comes first. The release date for Windows 7 is October 22, 2009 - if you pre-order you get a great OS at great prices. The pre-order prices are $49 for Windows 7 Home Premium Upgrade or $99 for Windows 7 Professional Upgrade. For now the offer is limited to the US, Canada, and Japan and will soon include France, Germany, and the UK.
For more details see the Windows team blog or the Windows 7 Pre-Order Offer page.
After midnight tonight you will be able to get more information from the Microsoft Store (until then this link will not work).