Google Chrome Frame is especially valuable for enterprise users, so Google added a MSI installer that helps IT administrators deploy the software in a network.
Microsoft has recently released the first beta of Internet Explorer 9 and showed that it can develop a browser that's fast, standards-compliant and better suited for running web apps. Unfortunately, Internet Explorer 9 can't be installed in Windows XP, which is still the most popular operating system. Even if Internet Explorer 8 has been released more than one year ago, almost half of the users haven't upgraded to the latest version of the browser.
Chrome Frame is already used by many Google services: Google Docs, Google Calendar, Google Reader, Orkut and other services will start to support it soon. Chromium's blog says that the main goals are to "to improve performance and ease the transition for users as they drop support for legacy browsers". After installing Chrome Frame in Internet Explorer 8, I noticed that Google Reader loaded much faster and had a better performance. If you want, you can load all the pages using Chrome Frame, but it's not recommended to do that.