As per the this KB Article 946202, On February 12, 2008 Microsoft will release the Windows Internet Explorer 7 Installation and Availability update to Windows Server Update Services (WSUS) marked as an Update Rollup package. Windows Internet Explorer 7 Installation and Availability Update is a complete installation package that will upgrade machines running Internet Explorer 6 to Windows Internet Explorer 7.
So this may require administrator action to manage the rollout. So be prepared.
Knowledge Base article 940767 contains more information on the Windows Internet Explorer 7 Installation and Availability Update
If you want to install Windows Internet Explorer 7 using WSUS today, you can import this package from the Microsoft Update catalog site by following the instructions in the section titled "Deploying Windows Internet Explorer 7 using WSUS."
If you have configured WSUS to "auto-approve" Update Rollup packages (this is not the default configuration), Windows Internet Explorer 7 will be automatically approved for installation after February 12, 2008 and consequently, you may want to take the actions below to manage how and when this update is installed. You will need to take action if:
•You use WSUS 3.0 to manage updates in your organization.
•You have Windows XP Service Pack 2 (SP2)-based computers or Windows Server 2003 Service Pack 1 (SP1)-based computers that have Internet Explorer 6 installed.
•You do not want to upgrade Internet Explorer 6 machines to Windows Internet Explorer 7 at this time.
•You have configured WSUS to auto-approve Update Rollups for installation.
Note This does not apply to Windows Vista because Windows Internet Explorer 7 is a component of Windows Vista.
Please check the KB 946202 for :