You could achieve something close to what you describe using standard features of dm Server 2.0.
Add a hosted repository to the repository chain of each dm Server instance, using standard repository configuration. Then define a hosted repository dm Server instance which has a watched repository in its own local repository chain. You can then drop new plans into the watched repository directory and these plans will then be available for deploying on the other dm Server instances.
To deploy such a plan on one of the dm Server instances, you need to drive the deployer API, preferably via JMX using the deployer MBean. Pass in a URI specifying the "repository:" scheme, e.g.
to deploy version 1 of com.foo.plan.