My suspicion would be that Trimble...as the new owners of SU...will help manage (sarcasm there) the 3DW for as long as Google needs it for populating Google Earth with manually made content. After that, it's anybody's guess.
We've already seen links on this forum to very impressive examples of scanned, auto-generated buildings and terrain. It's only a matter of time before Google Earth follows suit. As Pete (or was it Jeff?) suggests, SU is old technology for populating a globe...nether fish nor fowl...not fast enough to build an entire city, not accurate enough for professional purposes...and 3D buildings in general are nowhere near as practically useful as Street View.
I can't think that Trimble are going to be overly impressed with the vast majority of the content available, which makes me doubt that the 3DW will continue long in its present form. Vetting content is a non starter...SU is now way too big; and the rate of upload is stratospheric. The 3DW is based on the model of Objective Networks, the free precursor to FormFonts. ON was vetted...and it took a small army of student volunteers at CalPoly in San Luis Obispo to do it...and that was when SU was Pro only, with a tiny userbase. We are way beyond that stage now; and the logistics of control are simply impossible.
It may be OK limiting it to manufacturers etc, but the free exchange of models by casual users is utterly unmanageable on any kind of regulated basis.
