Vijay, If you have two different queues, the second ear shouldn't be picking it up as they would use different queue names or ports. if you have two pointers to the same queue, there could be a problem though.
Let me understand your scenario. You have MDB's in both EAR1 and EAR2. You want the messages to be consumed by the MDB's either in EAR1 or EAR2. In short you are clustering your MDB's in 2 different EAR files. Now all your business logic is embedded in EJB's that are deployed only in EAR1. You want all the MBD's to make calls to EJB's in EAR1... right?
Is this what you are trying to do? If yes, then in my opinion you will have to make remote calls to your EJB's i.e get a remote reference to your EJBObject and call the business methods. Your MDB's in EAR2 are just like any other java client trying to access EJB's, which has to be done through a remote reference.