vCloud Director actively polls each vCenter for information. If a Storage vMotion occurred, we would know it flipped over to a new Datastore within seconds (typically). This is the exact same nature as DRS and vMotion.
vMotion is a mechanism to allow DRS to function. We need them for the purposes of automatic load balancing, but vCloud Director isn't directly aware or triggering vMotions. What we will do is let DRS to its thing, and monitor the runtime of each VM. Then, if a vMotion does occur, we would update the vCloud Database with the new location of the VM (ESXi host or Datastore, or whatever).
SDRS + Fast Provisioning has some very specific things which need to occur. You need to be on vSphere 5.1 across the board, with current VMFS volume versions. Storage DRS in vSphere 5.0 is not linked clone aware. Even if you are on vCenter 5.1 + ESXi 5.0 ... that's not going to work for you. In this case Storage DRS would vMotion a linked clone, but create fully provisioned (thin) disks as an output.
SDRS is supported, with caveats.
I hope this explains my meaning. vCloud Director can interact with environments with SDRS enabled, but does not make Storage DRS recommendations or Storage vMotions.