Microsoft has now changed its public position: Service Pack 1 won't be required to run the new browser.
When Microsoft releases Internet Explorer 9, will it require Windows 7 Service Pack 1?
No. Internet Explorer 9 will install on systems that have either Windows 7 RTM or Windows 7 with Service Pack 1 (SP1) installed.
Internet Explorer 9 will require a number of patches before it can run; Microsoft has made many fixes to the Direct2D and Media Foundation APIs that the new browser heavily depends on. These fixes will be incorporated into Service Pack 1. However, standalone updates are also available, and the browser will install these if necessary.
IE9 will not require Windows 7 SP1
Posted on Monday, September 27 2010 @ 1:19 CEST by Thomas De Maesschalck