I recently wrote a whitepaper highlighting a great tool by one of our partners:  SoftArtisans OfficeWriter. 

OfficeWriter is a design tool and custom rendering extension that lets you use Excel and Word documents as report layout templates.  This differs from conventional out-of-the-box renderers that translate RDL-defined layout into HTML/PDF/CSV/etc.

It's a different way of thinking about report design, definition, and rendering.  It has certain limitations, but what you gain is an Office-based design experience and high-fidelity Excel and Word output from Reporting Services. 

If you have a specific need for rich Excel or Word export, I encourage you to read this article and contact SoftArtisans to get set up with an eval:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsql90/html/SQLSRSandOW.asp