If you're on Windows XP, Windows Vista or Windows 7—and if you're reading this site and a human, you better be—upgrading to Windows 8 is going to be dirt cheap and totally worth it: only 40 bucks.
The $40 upgrade price for Windows 8 Pro is part of an upgrade extravaganza promotion period lasts from the Windows 8 launch (sometime in fall) until January 31st, 2013. The way the cheapo upgrade works is through Windows 8 Upgrade Assistant, which will give you step-by-step instructions on how to download and check your PC to see if you meet up to the system requirements. If you hate downloading software and/or collect DVDs, you can get a retail copy of Windows 8 for $70 during this promotion period. Either way, it's going to be very affordable to upgrade to Windows 8. [Windows Team Blog via Forbes]