Normally the first I see of a new release is when it appears for evaluation on
http://www.hp.com/go/dataprotector but version 9 seems to have been released to customers on support contracts first.
The release notes are quite brief: nearly everything that has been announced as "new in version 9" was already available in the patches that took version 8.12 (Windows / Linux ). Integration with DataDomain, for instance.
The only obviously new option for most customers is that there is a new kind of backup-to-disk device ("Smart Cache") which you can use for VMware VEAgent backups. Then you can use the VMware GRE (Granular Recovery Extension) to extract out individual files from the Smart Cache device without having to restore the whole virtual disk first. This is obviously a big win for backing up virtual machines with large disks: it won't be necessary to do a file-level backup and a VMware backup.
Customers with large B6200 / B6500 arrays might find the federated de-duplication option useful because it means you don't have to assign engines to particular devices.
Greg Baker is an independent consultant who happens to do a lot of work on HP DataProtector. He is the author of the only published book on HP Data Protector (http://x.ifost.org.au/dp-book). He works with HP and HP partner companies to solve the hardest big-data problems (especially around backup). See more at IFOST's DataProtector pages at http://www.ifost.org.au/dataprotector