Since there are 7,000 different versions of Windows Vista, I thought this page and chart was pretty interesting because it tells you which IIS features are avaialble in what version. Again, I remind you from an earlier post that IIS supports multiple instances in Windows Vista.
Some of the biggest changes is that IIS isn't even fully included in the Starter/Home Editions. However, Windows Activation Service is present to support WCF. The Professional editions of Vista are actually designed for web developers and even allow 10 simultaneous connections as opposed to the usual 3. In fact, they support everything LongHorn Server does except for remote administration.
Take a look at the chart at the URL below. It has some good information in it.
IIS7 Features in Windows Vista Versions
Read the complete post at http://www.dotnettipoftheday.com/blog.aspx?id=288