There is no official date, but likely in the next few weeks. The official response from VMware is: "VMware View 5.1 together with the updated VMware end-user computing portfolio is expected to be available in Q2 2012."
I'm anxiously awaitng the release as well. I would like to put CRBC to good use. although I wish they would extend it to locally attached SSD's. FUSIONio currently does it with their PCIe SSD with the use of a special driver they give u.