Microsoft has extended the life of Windows XP beyond the date that Windows 7 gets its first service pack.
Previously it had been thought that the Vole was going to discontinue the right to downgrade from Windows 7 to XP when the Windows 7 SP1 service pack came out.
Now it appears, according to a Microsoft blog, that Microsoft has decided to extend downgrade rights to Windows XP Professional beyond the previously planned end date at Windows 7 SP1.
Apparently this will help maintain consistency for downgrade rights throughout the Windows 7 lifecycle, according to the Vole.

OEM versions of Windows 7 Professional and Windows 7 Ultimate will continue to include downgrade rights to the similar versions of Windows Vista or Windows XP Professional.
In the future businesses can continue to purchase new PCs and use end user downgrade rights to Windows XP or Windows Vista until they are ready to install Windows 7.
Enabling such rights throughout the Windows 7 lifecycle will make it easier for customers as they plan deployments to Windows 7, Microsoft said.