>> 1) I think we should look at these "extensions over and above" to see if we can change anything in JMS 2.0 to make it easier to use JMS on top of AMQP
If you wanted to make JMS really work over AMQP, you would need to make the changes in AMQP, not JMS 2.0. The correct place for recommending such changes would be the AMQP working group, not the JCP.
>> 3) AMQP remains as the most successful attempt of interoperability in MQ systems, including with platforms other than Java EE, and should be supported.
What's your measure of success? If you measure success by the number of messaging systems that really interoperate then STOMP is the most successful example of messaging interoperability so far.
Don't get me wrong, I think AMQP has it's place. The 0.9.1 spec is a good solid spec for implementing a message broker, the excellent RabbitMQ is a case in point. But AMQP is not rich enough to support JMS semantics, and AMQP 1.0 shows no sign of improving in that area (in fact AMQP 1.0 doesn't provide any broker semantics at all), so going down that road is likely to result in a dead-end.