It's nice to see a new CTP of Katmai on the Microsoft Connect site - I've been waiting to look at the new database mirroring enhancement which performs automatic page repair.  There are many other features in this CTP which are listed here https://connect.microsoft.com/SQLServer/content/content.aspx?ContentID=5470 which will be covered in the webcasts over August https://connect.microsoft.com/SQLServer/content/content.aspx?ContentID=6082