IISpeed is a new project which aims to bring the capabilities of Google PageSpeed platform to Microsoft’s IIS and ASP.net servers.
Google PageSpeed is already available for Apache and few other server platforms.
Features available already:
Minify, rewrite and combine CSS
Optimize images in html
Automatically sprite images
Strip whitespace and comments from html, trim urls
Url fingerprinting / cache extending
A/B testing with different settings
They are currently running a private beta with a select group of users. You can apply on their website.