Comments to goals:
It seems that so far SimpleGraph usage can be strong in GUI layer upon workflow/dataflow applications and engines.
This also can define a goal of Simplegraph Extended development.
It is also possible to go "Visio" way ie. to try to create Drawing editor, but I am a little sceptical about it, while we will directly compete with well established open source and commercial projects, and it will be far more difficult to deliver some real added value (compared say to Dia, JGraph or Visio).
Nevertheless we can utilize these projects and use them as optional gallery shape editors.
IMHO orientation to industry/business processes is more interestig and promissing target.
Comments to to-do list:
1-2 I think that gallery and svg "view" is higher in priority than svg designer/editor. As I have mentioned above, there are many running SVG projects, some of them can be found at http://www.w3.org/Graphics/SVG/SVG-Implementations
Use case for gallery designer than can be:
1. Design symbol in your favorite SVG editor.
2. Place svg in SGraph gallery folder under some distinguished name
3. Use it in your diagrams.
4. Consider publishing it as a part of SGraph project.
Event driven mechanism:
I am not sure about extending events. As I view SGraph mainly as an open front end to workflow/business process engines, I think that event proccessing is engines job. I have in mind data and time related events like OnTime, OnReceive, OnRespond, OnHold, OnPrint, OnStateChange ...
Another story are application events, that, Stefan has probably in mind.
To do list and priorities, inevitably, will change according to inteded applications. Seems that workflow needs dictates following roadmap:
1. SVG enabled SGraph (use case: open svg file, click on canvas, see the symbol)
2. XML graph save format (although I already have one implemented, I think that it should be revised).
3. Highly configurable node/link property editor that will enable to create new editors for different data structures without the need of program recompilation.
4. Gallery mechanism