SU has similar "problems" - there is so much content in the warehouse and 90% of it is too high rez, poorly modelled, badly scaled, filled with useless geometry or otherwise unusable without editing.
Similarly a good library of bump-maps and textures is normally premium content from third parties.
From a development point of view I would be hesitant in competing with the likes of SUPodium for shipping with textures or models: I would concentrate on improving and adding features to the live walk-through that is at the core and let users worry about what to model and how to skin it. I think that a tool to create multi-layered, seamless textures with associated bumps, transparencies and reflective maps would be cool, but I can do that with image editing software. (But this is just my thoughts.)
In saying that, I have used a few different softwares for the kitchen design industry and each manufacturer has their own libraries of colours and textures for cabinets and worktops - there is a saying about "re-inventing the wheel"...