The SQL 2005 SP2 has just been out for a couple of weeks now.. It brings a nice new feature in terms of reporting:

• Microsoft SQL Server 2005 Reporting Services Add-in for Microsoft SharePoint Technologies:http://www.microsoft.com/downloads/details.aspx?familyid=1E53F882-0C16-4847-B331-132274AE8C84&displaylang=en

With this add-in you can can use its Report Viewer Web Part that provides report viewing capability, export to other rendering formats, page navigation, search, print, and zoom. Combine this web part with reports generated for Project Server 2007, and you have a very nice reporting feature that you can integrate in your EPM portal.

To get started with using Reporting services and Project Server 2007, check Treb's blog: http://blogs.msdn.com/project/archive/2007/01/30/sql-server-reporting-services-report-pack-for-project-server-2007.aspx