I just found this blog post on iis.net and applied it to my WordPress site. The site does seem a lot faster but it could be the car wash effect. You know, when you get your car washed and somehow it makes it faster. Also known as the gas tank effect.
http://blogs.iis.net/ruslany/archive/2010/03/05/make-wordpress-faster-on-iis-with-wincache-1-1.aspx