I just posted a blog about IIS6 compression. I was wondering if IIS7 compression was much different. After some searching, here are some links I found regarding IIS7 compression. I enabled this successfully on my IISLogs.com server and is working great. A quick search on Technet doesn't have any IIS7 compression info.
Migrating an ASP.NET app to IIS 7
Changes to compression in IIS7
IIS Compression by Bernard Cheah