Mountain Lion upgrade for organizations
The general advice is that Apple has sales channels (within the retail stores as well as without) to assist organizations understand the various programs and licensing terms. Additionally, organizations typically get tools to assist with license management, support and deployment.

If you don't have a sales contact yet, you could start with this somewhat dated, but very nice white paper on the issues for deploying OS X in a large scale setting:

http://www.apple.com/education/docs/Apple-SolutionsSystemMgmt.pdf

There are more up-to-date presentations for the App Store, but I haven't seen them published on the web.