I've got some good news for the bean counters...
Our plan is that the ability to deploy database packages will be a core component of the Deployment Manager product. Therefore, we will be wrapping up the use of SQL Compare on the agent so that you will not need to explicitly install or license SQL Compare on those machines.
This is something we are working on 'right now', and we expect to deliver our Database Deployment solution during Q1 2013. Hopefully, this should be end of Jan/early Feb.
In the meantime, if you want to start doing database deployments you will have to install SQL Compare on each agent. However, when/if you come to purchase Deployment Manager, our sales department will be able to work with you with regards to the licensing of Compare on those machines.
I hope that answers your question, please let me know if you want more info.