SQL Server Denali – Column Store indexes – The biggest thing in Denali
If you saw the keynote then you will have seen the awesomeness of the columnstore indexes that were demoed. If you’ve used power pivot then you will have experience the same technology in vertipaq (tm) the engine underneath powerpivot.
Read more here http://download.microsoft.com/download/8/C/1/8C1CE06B-DE2F-40D1-9C5C-3EE521C25CE9/Columnstore%20Indexes%20for%20Fast%20DW%20QP%20SQL%20Server%2011.pdf
I personally see this as the biggest thing in Denali. However I also fear that people will create them not knowing they are static and also will create very wide tables and just put columnstore indexes on top.
Pleas note this is not in CTP 1.