In future community technology previews (CTPs), use this forum to file questions and discussions about how PowerPivot for Excel works in SQL Server code-named "Denali."
For CTP1, the
What's New (Analysis Services) topic in Books Online states...
...that there is no SQL Server Code-Named “Denali” version of PowerPivot for Excel in this CTP release. Please use the SQL Server 2008 R2 version of PowerPivot for Excel to publish a PowerPivot workbook to a SQL Server Code-Named “Denali”
PowerPivot server.