I too am pretty curious about doing this, but I am wondering if SDRS has any impact on fast provisioning? I have seen an article recommending against it, but vCAT3.1 shows it as supported. These might be deeper questions that require another post, so just let me know if I need to start another one.
Also in the last part of your post you mention that, "Storage DRS and Storage vMotion is something vCloud isn't particularly aware of at this time.". Does that just mean that the vCD database isn't aware of where the VM actually is until the next refresh/reconnect?