Sorry for not responding to your comments in time. Missed this somehow.
I've implemented the functionality with xmlbeans and java implementation on top of it. This will be included in the upcoming uima-as 2.4.0 release. Its working well. Current implementation supports dynamic generation of UIMA-AS DD in java. Post release, I plan to enhance this with an ability to take a DD, generate java classes (via xmlbeans) and use Spring framework java configuration to wire things up. Details still to be worked out.