IE9 is pretty good... It's introduced a minimalist design, boasts better Internet protection, and runs each window as it's own process. However, Google Chrome has offered all of these features since it's release. IE tends to be lax in the extension department, while Chrome offers excellent extensions that provide a better browsing experience. Additionally, Chrome is supported on XPsp3 and up... IE9 will eventually be released as a Windows 7 SP1-only program.
But try it out and let us know how it works... I haven't spent much time with it as of yet and haven't had a chance to run acid tests or load times in different browsers.