Perspectives, like drill-through, are another Analysis Services feature coming to PowerPivot.
Perspectives allow you to expose a subset of your model to the end users. Let's say you created a PowerPivot model on Sales, Purchase and Inventory with 15 dimensions, each with about 10 attributes and a total of +50 measures. This model can be a little bit overwhelming for e.g. the Sales Manger.
We can now create a perspectives that contains only the most important attributes and measures related to Sales and expose that to the Sales Manager.
Before you can create perspectives, you must switch to PowerPivot in advanced mode.
Next you choose Perspectives in the Advanced tab, and start creating your perspectives.
In the Pivot table view in Excel you can choose the perspective from the top drop down-box in the PowerPivot Field List.
Another nice Analysis Services (Enterprise!!) feature coming to PowerPivot.