I'm excited with the new changes and functionalities that Windows 2008 will provide to the enterprise and hosters. To mention some of these features, Windows 2008 provides a minimal version of the OS (Server Core - the most efficient Windows version ever), expansion in the capabilities of powershell and how the server can be administered (you'll be able to obtain a script for almost any correspondant UI control or task), additional HA features are incorporated/enhanced into Windows Server (failover clusters, Network Load Balancing, dynamic hardware partitioning, robust storage options, and advanced machine-check architecture), enhanced OS-virtualization mechanism to consolidate and optimize the resources in the DataCenters (Hyper-V), let's don't forget IIS 7.0 and its additional features (PHP integration, security enhancements, larger no. of web-sites supported per server).
If you want to know more about these features, check out the following set of online videos which presents the capabilities of Windows 2008:
Windows Server 2008 Deployment Overview - Michael Niehaus, Tim Mintner The 10 Most Important Things About Failover Clustering - Jim Teague Power Management: Windows Server - Stephen Berard Dynamic Partition: Windows Server - Davis Walker Windows Server Longhorn - Iain McDonald Windows Server virtualisation - solution scenarios - David Hitchen Windows Server 2008 Kernel Advances - Mark Russinovich Active Directory Domain Services in Microsoft Windows Server 2008 - Stephanie Cheung Virtualization in Windows Server - Mike Neil Managing Windows Server 2008 with Server Manager - Dan Harman Using Group Policy with Windows and Windows Server 2008 - Mazhar Mohammed, Derek MelberMicrosoft.com: Employing Windows Server 2008 and Internet Information Services 7 - Paul Wright, Brad LeRoss Living the Longhorn Life: What's Up With Windows Server 2008 - Mark Minasi
Feel free to share with me your views and comments.