In a previous blog I talked about the value of PerformancePoint for the finance function. Here's a link to a great post by John Colbert who writes for b-eye. Now whether you think Excel is good or bad - and believe you me I'm the first to suggest it has it's limitations it is nonetheless the default application for end user data analysis. Often we get bogged down talking about (and I include Microsoft in this) infrastructure to make BI and CPM more pervasive but John's published some great articles on why BI needs to be driven by the end-user. 

End user Predictive Analytics

Performance Management and the End-User

On PerformancePoint Server