Latest CRM 4.0 rollup released on 17/12/2009.
Rollup 8 can be uninstall on server
Rollup 7 is cumulative.
Rollup 1,2,3,4,5,6,7 are not prerequisites for server portion.
Update Rollup 7 is a prerequisite for Microsoft Dynamics CRM for Microsoft Office Outlook and Microsoft Dynamics CRM Data Migration Manager.