UML 2.0 Roadmap Draft[Kobryn99]
 
 
Heavyweight extension mechanisms and profiles
Activity graph semantics independent of state machines semantics
State machine generalization
Generalization of association
Variations of aggregation
Physical metamodel based on strict-metamodeling approach
Support for 
- change management
 - diagram interchange
 - rule-based modeling
 - business organization modeling
 
Cleanup constructs not used based on feedback from vendors and users