Drools Flow, a sub-module of Drools, was indeed offering similar features compared to jBPM5. Drools Flow and jBPM have merged however, and the Drools project is currently also using jBPM5 for their process requirements. Obviously, the other features of the Drools project simply continue.
So both projects will be supported by JBoss, however jBPM5 is the solution for business process execution and is used by Drools.
Kris