If you're currently running an older version of Windows and want to upgrade to Windows 8 when it's released, you might want to look at Amazon.com's upgrade deal.
Windows 10 review: Microsoft goes back to the future
Windows 10 ISOs now available to download
Poll: Is Windows 10 ready for its launch?
Hands-on: Phone Continuum in Windows 10 Mobile
windows 10 phone continuum
Hands-on: Windows Hello biometric log-in