JAXB 2.2 API should be changed to work with 2.1 implementation in JDK when one
is not using 2.2 features.
For people using JDK 6, copying jaxb-api.jar to JRE endorsed dir is one option,
but that breaks the existing old jaxb applications as it no longer can find the
default provider for the jaxb api in JDK unless one configures jaxb 2.2
implementation via classpath.
JAXB 2.2 API should be fixed to use the default provider in JDK when it can't
find a suitable provider via meta-inf/services. This would make atleast 2.1
applications work as it is without any changes.