PowerPivot - a new way of MS BI integration with SAP BW and non-SAP data sources

PowerPivot has a feature to define "relationships" between different tables which allows to do a "join" between different data sources. The goal is to achieve the same thing as with the new Lookup function in SSRS 2008 R2 - shown in the blog which was mentioned in the first section above. PowerPivot has no native built-in direct SAP connectivity. But there are different ways to access SAP data out of PowerPivot.