Microsoft is set to push IE 7 out via WSUS on Tuesday

From a technet update email

Volume 10, Issue 3: February 6, 2008

"On February 12, 2008 Microsoft will release the Windows Internet Explorer 7 Installation and Availability update to Windows Server Update Services (WSUS). 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. Customers who have configured WSUS to "auto-approve" Update Rollup packages will automatically upgrade machines running Internet Explorer 6 to Windows Internet Explorer 7 after February 12, 2008 and consequently, may want to read Knowledge Base article 946202 to manage how and when this update is installed. For more on the Windows Internet Explorer 7 Installation and Availability Update, read Knowledge Base article 940767."