Hallo
Just a quick question on the features for the latest version of View(Horizon View) 5.2 
Why don’t VMware create the option to create a tiered type pool setup? Your pool limitation is set to 2 000 desktops now, yet you are limited to the amount of available IP’s on the subnet/VLAN. Now, with View 5.2 you can now add additional port groups in your config instead of working off of multiple images, or with 1 base image and multiple snapshots or even going the single subnet/VLAN setup which means one BIG broadcast zone. The network guys will LOVE you for this thou.
The adding portgroup or subnet option, is still V1 thou, thus this can only be done via Power CLI.
My suggestion is to make use of a "storage DRS" type setup where you have a single port of call pool, with sub pools comprising of multiple base images. A sub pool can then be placed in maintenance mode, changed or updated and then simply pulled back into the “master” pool for usage.
Keep in mind that this will mean that your VM’s config needs to be with same app’s etc, as this will be for a call centre type setup.
That’s my 10cents.