December last year I participated in the 71-659 beta exam. Yesterday I got the message that I passed this exam.
The exam is all about Windows 2008R2 Server virtualization. A lot of cluster, iSCSI and MPIO questions but also a couple of RDS questions. Further questions about the different tasks you can encounter when using virtualization, Backup, export/import, P2V/V2V and so on. Some basic troubleshooting and performance monitoring is also part of the exam.
If you have experience with Hyper-V/SystemCenter Virtual Machine manager in a clustered environment, the exam isn't that difficult, but the beta exam was over 70 questions so it won't be the easiest Microsoft exam on the planet.