Allowing community members to directly edit and improve the scenery could be amazing if handled correctly. Obviously changes would need to be reviewed and approved so it would take a while, but over time the world would become more and more accurate.
I guess once community members became trusted and were shown to be reliable their access could be increased and they could potentially be allowed to edit and upload? That way dedicated scenery modders who wanted to transform a region and were on a trusted member list could do it much more quickly.