in server, will i only be able to look up what on my home folder, or will i be able to search other users public folder (or another folder that i would have access too)
I guess my answer varies greatly on how much of an NDA I'm under, being 24 hours away from the release and many copies already in the wild...
Is your question asking about using spotlight locally on the server to search for files? Then yes, Spotlight should be able to search any local volumes that you have permission to access, as with all search technologies.
Or are you asking if you could connect to a share on a Server and search that with Spotlight? That's a little more specific to the spotlight technologies and is in that grey area for about 29 hours.
If you want a little more info about this, you can read up on how Spotlight works and catalogs data and contemplate that methodology a bit....
If you have normally access to that location - it can find and index.
If you DON'T have access to a folder - it does not index or access. So it repeats the same privileges. Ie if you ahve e.g. stuff on your XServe RAID, it should index them if you have access to them...