VDP is ideally meant to be run on it's own hardware, I had it running on an old HP G1 blade because of it's resource requirements...it's based on EMC Avamar which I believe was shipped with it's own hardware appliance.
I received a call from VMWare stating that VDP will take up as much resources as it can possibily take, if you are running it in a DRS cluster you should put a cap on CPU/memory resources. VMWare don't do this out of the box. It won't affect operation of the appliance, but backup jobs will take more time to complete.
See my post here
http://communities.vmware.com/message/2228577#2228577
I ended up looking into alternatives, as VDP was causing too many issues in my enviroment.