Microsoft has already seeded its most popular patching tool for corporate users with a reference to Windows 7, its planned successor to Windows Vista.

Windows 7 Client is listed on the product-selection screen of Windows Server Update Services, which lets IT managers feed security updates to PCs and servers. Microsoft said the appearance of Windows7 in WSUS wasn't an accident. "This is a standard step in the Windows development process," a spokeswoman wrote via e-mail. She said that the reference was added for testing purposes.

Windows 7 is expected late next year or in early 2010. Microsoft started talking about it publicly earlier this year, and the Windows development team launched a Windows 7 blog this month.