Bryan,
Page Speed only runs in Firefox, but the recommendations it makes
apply to all browsers. In fact, several rules are there to avoid IE
specific issues.
Chrome did not exist when we started writing Page Speed. There is
no way to write an extension for Chrome yet. They are working on it:
http://dev.chromium.org/developers/design-documents/extensions
When Chrome has a extension API, we will consider porting Page Speed to Chrome.
Sam