Microsoft is going to make it easy and affordable to upgrade to Windows 8 Pro once it is available. A blog post on the Windows Team Blog states, " Starting at general availability, if your PC is running Windows XP, Windows Vista, or Windows 7 you will qualify to download an upgrade to Windows 8 Pro for just $39.99 in 131 markets. And if you want, you can add Windows Media Center for free through the “add features” option within Windows 8 Pro after your upgrade."
This makes it a no-brainer for those who want the latest and greatest version of Microsoft's OS. The Windows Upgrade Assistant application will make it easy to uprade the software and will aslo scour your hard drive for compatibility issues from your applications.
Once you purchase your upgrade, the Windows 8 Upgrade Assistant kicks off your download. It has a built-in download manager that allows you to pause and continue your download at any time as well as a check to ensure your download completes successfully.