Excluding your endpoints, do you have a current cost accounting of the entire infrastructure capex, opex, software licensing, and any professional services behind your existing 2000 seats? I work extensively in this field and the numbers they are throwing out are extremely competitive with existing on-premises View or XenDesktop implementations I've been involved with.
We're running on 4-5yr old hardware... and our maintenance contracts, even though high wouldn't amount the yearly costs to use this service. This is at least a decent option if you're planning on new infrastructure.
What about the costs of running the hardware - power, cooling, network switches, storage arrays, datacentre rental (or opportunity costs of using a server room versus more desk space for example)?
Not saying it still wouldn't work out cheaper for you, but worth bearing in mind.
