I've really only been working on the truss plugin for about a year now and there is a lot more to be done as well as two more plugins that I am hoping to get started on into the new year:
Medeek Structural Plugin
Medeek Wall Plugin
The structural plugin will deal less with the actual framing geometry and more specifically with the lateral and vertical engineering of the structure. It will be geared toward other structural engineers with the intent to automate residential structural engineering as much as possible.
Lateral:
Wood Shear Walls (segmented and perforated), Diaphragms (roof)
Vertical:
Beams, Headers, Joists, Rafters, Footings, Posts, I-Joists,
Uplift:
Rafters, Trusses
What will make this the killer app is that the 3D model will be able to automatically propagate the loads down through the structure while at the same time allowing the user to create the structure's geometry in an intuitive and friendly 3D environment - SketchUp.
Of course the real power of such a plugin only becomes apparent when you create a model and then decide to build that same house or structure in a different location with different site criteria. Rather than having to start from scratch you simply enter in the new wind speed, ground snow load, and seismic design criteria into the model and the plugin recalculates the entire structure and then alerts you on any members that are undersized or over stressed. This would be particularly beneficial to homebuilders who have a set number of model homes they use but build in various locations.