A nice list of all new features in IIS 7.5 (the one in Windows Server 2008) is located in Michael Pietroforte post – Windows Server 2008 R2 new features – the complete list – Part 3: IIS 7.5 and Performance.

Internet Information Services 7.5 (IIS)
  • PowerShell provider for IIS 7 has more than 50 new cmdlets
  • Administration Pack extensions: Database Manager (SQL Server management within IIS Manager), Configuration Editor (generate scripts with a GUI to automate administrative tasks), IIS Reports, Request Filtering (HTTP filtering, URL rewriting, etc.)
  • One-click publishing in Visual Studio 10
  • Web Deployment Tool (formerly MS Deploy): Deployment, management, and migration of Web applications, sites, and entire servers
  • Configuration Tracing: track configuration changes to IIS and applications
  • New performance counters
  • .NET support for Server Core
  • WebDav integration (was available before as a separate extension)
  • URLScan 3.0 integration: restricts the types of HTTP requests (was available before as a separate extension)
  • FTP server services: integrated in the IIS administration interface; new .NET XML-based *.config format; virtual host names for FTP sites; improved logging
  • Integrated extensions: new kind of extensions that appear to be an integral part of IIS

 

See more detailed info at the IIS team post – IIS7 in Windows Server 2008 R2.