cocoon-sample and cocoon-archetype-block do use cocoon-maven-plugin
to prepare and deploy a block to a local jetty, featuring some class
It could be an idea to remove cocoon-maven-plugin and profit from
class reloading features of Tomcat 7  (for instance) with support
of Cargo for managing and configuring Tomcat instance.
We may, of course, continue (actually, start again) support for
cocoon-maven-plugin. but I have more a feeling that we could better
concentrate on C3 development, instead.
Apache Cocoon Committer and PMC Member