We're working a lot on Obeo Designer 5.0 - release planned for Q1 2011 , on the traceability support and the next-gen model to text transformation language.
Concerning the editing and diagraming support changes are more subtles though powerful. Here is a quick glimpse on the latest milestone :
The most visible change is the work on the diagram ergonomy, the user interface has been cleanup, streamlined and features are more accessible. The global toolbar has been replaced with a dedicated toolbar embedded in the diagram editor providing access to the filters and the enablement of layers.
The contextual actions have been re-organized too.
If you're used to nice Eclipse editors you'll be happy to learn that the "Quick Outline" (summoned thanks to CTRL+O) is available in the diagrams now.
Just type in any word here, and the corresponding model element will be revealed in your diagram.
More interesting is the redesigned support for diagrams ! You can, for any kind of model being UML or your own DSL, specify and leverage a diagram editor keeping the model sequence order in sync with the diagram ordering.
you have the same level of customization that for the other kind of diagrams, you can change the shapes, colors and use the sequence diagram constructions like lifelines, messages and executions.
Here we're not using UML but our own "interactions" DSL which refers to another DSL describing domain entities.
As a sidenote, you can now have a color definition which is interpolated on a color palette depending on some model computation. Here we have a nice shade of green depending on the level of execution.
In a nutshell this new release will bring you more control, to the visual aspect and interactions on the tooling, the ability to define sequence diagrams, still keeping the complexity to a minimum : no deployement requirement, one file describes the whole design environment which you can test and try without even starting an Eclipse runtime.
It doesn't mean you can't deploy your environment as a set of plugins with proper dependency checking thanks to P2, it's just that you don't have too.
If you don't know about Obeo Designer and you want to setup a dedicated design + transformation toolchain for your domain, have a look here.
Here is a flash demo being a recap of these features :