CF Cluster - Application Scope

Short answer: no

Long answer: you may be able to accomplish the same thing (or close to it) by re-engineering your application with some sort of event-listener pattern, using a shared resource to register events (e.g...a database)

Thanks for the reply Grizzly. Is there a way to "communicate" to the other servers in a cluster that a change (any change, but in this case, an application variable) has been changed?

It is not possible to keep the application scope in-sync across a cluster.

To clarify, it is possible to replicate the session scope in a cluster (via J2EE session replication), but the application scope only exists in its own "sandbox" so to speak on each server.

Session scope aside, if you're looking to share data across a CF cluster you should do so with a shared resource (e.g...a shared file system or preferably, a database)