Mike Volodarsky from the IIS 7.0 team recently created a new blog and has been posting up a storm of great IIS 7.0 related posts. Mike owns the "integrated pipeline" and "server core extensibility" aspects of IIS7 - which among other things now allow you to write ASP.NET/.NET HttpModules that can participate in any web request to the server (for example: you could implement forms auth and role security for ASP, PHP, Java requests). This gives you more power than ISAPI extensions/filters today - and best of all you can use any .NET language to build them. I definitely recommend subscribing.
If you haven't checked out www.iis.net yet, then I'd also recommend setting aside a few minutes to review some of the great content on it. http://blogs.iis.net aggregates blogs from team members. Here is the RSS feed to subscribe.
Hope this helps,