Power Pivot SQL Server 2008 R2

I've seen Power Pivot in SQL 2008 R2 and I like the functionality... to a point. The list of fields does not seem to be able to be arranged in any order and you can't create hierarchies of fields (or so it seems). I've heard that in Denali, you can arrange fields in hierarchies. Does anyone know whether this means that the feature is only available when you connect to a Denali database, or whether the free Excel add-in will be updated for other (non-Denali) users?

Also, does anyone know a way of grouping on the fly. In normal pivot tables it's easy (and extremely useful). I can't see a way to do it in PP. By grouping on the fly, I mean deciding while you're analysing, how you might want your attributes grouped.