Seen on Scott Guthrie's blog, is an announcement for an upcoming release of IIS Express.

IIS Express offers the functionality of IIS 7.0, even back on Windows XP, running as a user mode application (i.e. admin rights not required to run this  ad hoc web server). Simply right-click on a folder, and you can start an instance of IIS running from that folder. It appears that most of the major functionality of IIS 7.0 (including the modular architecture) is included. Interesting times.