Yes you are going to want Windows 2008 in your shop. We've been running 2k8 for over two year sin production and I'm very proud of the product we're shipping shortly. Some of you will want to start thinking about what's new in the OS, what has changed, performance, and deployment. Here are some docs/links that will help get you started.
This document describes new features and technologies, which were not available in Windows Server 2003 with Service Pack 1 (SP1), that will help to increase the security of computers running Windows Server 2008, increase productivity, and reduce administrative overhead.
These topics apply to the next release of Windows Server 2008, based on the functionality expected to be included in the Beta releases in 2007. They do not describe all of the changes that are included in Windows Server 2008. Instead, they highlight changes that will potentially have the greatest impact on your use of Windows Server 2008 and provide references to additional information.
•Performance Tuning for Server Hardware
•Performance Tuning for Networking Subsystem
•Performance Tuning for Storage Subsystem
•Performance Tuning for Web Servers
•Performance Tuning for File Servers
•Performance Tuning for Active Directory Servers
•Performance Tuning for Terminal Server
•Performance Tuning for Terminal Server Gateway
•Performance Tuning for File Server Workload (NetBench)
•Performance Tuning for Network Workload (NTttcp)
•Performance Tuning for Terminal Server Knowledge Worker Workload
•Performance Tuning for SAP Sales and Distribution Two-Tier Workload
All other inquiries head to the Technical Library for 2k8.
BTW when you install 2k8 and notice that in WinVER or System Properties it shows SP1, don't be alarmed this is by design. Vista SP1 and Win2k8 were developed in parallel, so fixes in the code were included in both versions. This isn't the first time, when we rolled Windows 2003 x64 edition out the door it went as SP1 too...