If I create a deployment (a.jar) and then a second deployment (b.jar) which depends on it (deployment.a.jar in the dependencies part of the manifest), deploy them both and then re-deploy a.jar, I get:

16:37:13,458 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-4) MSC00001: Failed to start service jboss.deployment.unit."b.jar".POST_MODULE: org.jboss.msc.service.StartException in service jboss.deployment.unit."b.jar".POST_MODULE: Failed to process phase POST_MODULE of deployment "b.jar"
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:119) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) [rt.jar:1.7.0_09]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) [rt.jar:1.7.0_09]
at java.lang.Thread.run(Thread.java:722) [rt.jar:1.7.0_09]
Caused by: java.lang.NullPointerException
at org.jboss.as.ee.component.deployers.InterceptorAnnotationProcessor.deploy(InterceptorAnnotationProcessor.java:43)
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:113) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
... 5 more

Everything else works - they deploy fine, in the right order, on startup or first deployment. Re-deploying b.jar after this error also makes b.jar deploy.
However, a key point of the hot-deploy feature for us is to have dependency redeployment work properly.