If you have needs around exposing corporate data from business systems into SharePoint, take a look at the following documents.  They describe the many ways SharePoint can be used for enterprise user interface and a composite application platform.

SharePoint: A platform for enterprise mashups
http://www.microsoft.com/downloads/details.aspx?FamilyID=3bfa11be-815a-414d-b69f-c2add07d8733&displaylang=en

Integrating LOB Systems with the Microsoft Office System
http://msdn.microsoft.com/en-us/library/bb896607.aspx

Office Business Applications: Building Composite Applications Using the Microsoft Platform
http://msdn.microsoft.com/en-us/library/bb220800.aspx