Here's an idea to export an edited *.veg project to DVDA without having to render the whole thing first:
1) Would render transitions, effects, pan / crop, etc., to .avi, .mpg, etc. according to Vegas Project Properties assuming consistency with DVDA import parameters.
2) Would render a separate AC3 or PCM audio file consistent with DVDA import parameters.
3) Would save as a DVD Architect compatible *.dar project file that could be opened (and rendered, if necessary), add menus, etc. and authored in DVDA
4) Expand the rendering options within DVDA to include all the MainConcept options currently available in V8 with a warning if they do not fit the media.
Too simple? Please post responses / ideas, etc.