Microsoft is pushing test updates to Windows 7 Beta (Build 7000) users via Windows Update. These updates won’t have any features, fixes or patches these are just test updates pushed to test the Windows 7 update process.
These test updates will be available through Feb 24th, and they won’t be installed even you opted for automatic updates. Users have to manually install these updates through Windows update. If you prefer not to install them you can do so and hide these files.