I am migrating to plugins v2, and just found that my components are not longer StateAware, as documented here.

I.e. my module:

public class WorkflowsInitializer implements StateAware {

    public void enabled() {
        // do something
    }
}

which I define in atlassian-plugin.xml

    <component name="Workflows initializer" class="com.comalatech.confluence.workflow.WorkflowsInitializer"
               key="workflowsInitializer"/>

WorkflowsInitializer.enabled() never gets invoked.

I also noticed that the component modules are not longer enableable/disableable in /admin/plugins.action, which is not a big deal, but probably that's the reason why they're not getting enabled.

See Matt's comment below for details on what the situation is now. We need to update the StateAware documentation, and probably the Component plugin module page as well.