I have been waiting to see this transition of SharePoint 2007 currently working in classic mode ASP.NET pipeline even when running under Win 2008/IIS 7.0.
Win 2008 and IIS 7.0 has improved a lot and has been very modular. IIS 7.0 has ability to operate the application pool under Integrated mode ASP.NET pipeline which essentially means that there are no more two more pipelines to manage. Back in IIS 6.0 days IIS had its own pipeline and the ASP.NET had a different pipeline. There are certain scenarios when you would want to access the IIS pipeline to manipulate the request and response, the only way to was to write and ISAPI module using Visual C++ which is pain and not lot of organizations had these skills. To learn more about how can you make use of this Integrate mode ASP.NET pipeline read the following article "Enhance Your Apps with the Integrated ASP.NET Pipeline" by Mike Volodarsky
With C# getting popular and abundance of resource available it was good for Microsoft and IIS 7.0 platform empowering the developer community to write application leveraging the IIS pipeline and ASP.NET pipeline all within single managed module using C#. This all comes with Integrated mode pipeline. IIS 7.0 for backward compatibility has a option to run application under Classic mode.
SharePoint 2007 was not built to make use of Integrate mode pipeline. But the newer version SharePoint 2010 naturally has the ability to work in Integrated mode. Here is how my screen shot look in IIS look like
