Microsoft.com has posted a nifty grid at https://www.microsoft.com/windowsserver2008/en/us/compare-features.aspx that shows you which versions of Windows Server 2008 are required for the new features:
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Internet Information Services 7.0
Covered by server license. No incremental licensing requirements.
Network Access Protection
AD Rights Management Services (RMS)
Covered by server license, but incremental RMS CALs required, similar to Terminal Services.
Terminal Services Gateway and RemoteApp
Covered by server license, but incremental TS CALs required, similar to AD Rights Management Services.
Windows Deployment Services