There are some changes in 5.8 that may require some code change

1. New modules may effect your maven pom dependencies
   activemq-core has been replaced with activemq-client and activemq-broker. The various message stores have their own activemq-xx-store module. The uber module activemq-all remains.
2. Changed JMX Mbean ObjectNames will effect scripts or tools that directly reference Mbean names
   All mbeans now share the type=Broker attribute, which gives them containment. In this way, consumers hang off of destinations, which hang off the broker.
   The different Mbean types are identified by the presence of specific identifiers in their ObjectNames. The mapping from old to new ObjectName is as follows:

   Type	Old Name	New Name
   Broker	Type=Broker	type=Broker
   Destination	Type=Queue|Topic,Destination=<destination identifier>	type=Broker,destinationType=Queue|Topic,destinationName=<destination identifier>
   Connector	Type=Connector	type=Broker,connector=clientConnectors
   NetworkConnector	Type=NetworkConnector	type=Broker,connector=networkConnectors
   Connection	Type=Connection	type=Broker,connector=*,connectionViewType=remoteAddress|clientId

3. OSGi integration has changed. The full details are at OSGi Integration. In summary:
   1. There is a single uber OSGI bundle
   2. The broker and webconsole are now configured via config admin pid files through an OSGi managed service factory.
4. The ActiveMQ binary file bin/run.jar has been renamed to bin/activemq.jar.