So I see that a lot of people have already converted quite a bit of areas successfully, yet we cannot share them at this point.
I was willing to share 3D work of special elements and converted scenery and was hoping that all coming together there would be quite a bit of user created content shared and that the overall flying area would progress nicely.
From reading this forum on the subject, there seems to be a copyright concern with sharing geoconverted terrain. I would think it falls under "derivative" work of copyright laws, much like taking a picture of a painting (or of another picture). The transformation (geoconvert tool, plus adaptation to the IPACS format) should be sufficient to justify "derivative work" and thus creates a new copyright on the created content.
So the newly created content belongs to the author (the person doing the conversion) which he in turn can dispose of at will (sell, give away, put in public domain, etc..)
USGS data is public domain, so even if it were to be used as is (no transformation), there shouldn't be any issue.
Any definite answer on the subject?