One way to handle this might be to create a "template" DC that is shared on the 3dwarehouse and contains all of the "standard" attributes for a given industry. If you going to create, say, a window, then you grab that template and build your window inside of it.
The really hard part is getting a standard that covers everyone's needs while also being relatively simple. Ideally, it would be best to find an existing data standard to follow rather than create our own, but we may find that it's more practical to create smaller, simpler subsets of these giant standards.
I like the idea, but I'm not an architect so I don't know what more to say, except that the SketchUp team would be happy to entertain proposals for establishing lists on our website or collections on the 3d warehouse for this kind of thing.