The migration to jBPM5 will be also agresive because it does not keep backguard compatibility with jBPM3,as far as I know. The more sweet migration should be done to jBPM4 but this library has been abandoned and nobody maintains it, and seems to have several important bug.
This is sad, I know. But we need to leave jBPM3 some day because prevent us to upgrade to newer version of Hibernate.
Of course comments and ideas are welcome.