Typical server deployments will not get much from enabling SuperFetch, especially if you run disk defrag a decent amount, or use a 'in-the-background' defragment tool like
Diskeeper. If you are using 2008 as a desktop operating system, it becomes more compelling.
By default, the Superfetch service is installed on a Server 2008 system but left disabled. If you try to enable it, the service won't start. This is easily fixed with 2 registry entries lifted from a Vista installation.
The registry entries in question are:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters]
"EnableSuperfetch"=dword:00000003
"EnablePrefetcher"=dword:00000001
If you want a cookie-cutter premade .REG file, you can download it
here.
For those following my '2008 as a Desktop' saga, I'm happy to report I have Diskeeper running under Server 2008 now too. The only thing I am missing from Vista these days is Dreamscene.
I *almost* have the Hyper-V Integration Services running on a XP instance, but I suspect that won't be functional until at least the release candidate or later.
