Recently we performed our upgrade to vCenter 4 that I have discussed before on this blog. vCenter 4 introduced Datastore permissions as a new feature. We have a Desktop Support Role setup prior to the upgrade that allowed out desktop professionals to deploy and manage our VDI (no broker yet) workloads.
They had the "Browse Datastore" permission which required before to do their work. After the upgrade to vCenter they could no longer deploy the desktop template. The error message was very clear as to the problem though "You do not hold the privilege 'Datastore > allocate space' on the Datastores connected to the Cluster."
The fix was simple, edit the desktop support role and check the box under Datastore called "allocate space".