Note: This is a work in progress, and chances will be made before the final release (v3.0.0).
The upcoming 1.6.7 update is titled "The Terrain Update", because of it's extensive terrain tweaks and additions. The grass were flooding the terrain and are removed, only some bushes remain, to keep the terrain more rocky, so it's more like the mountain it's based on; Haglebu (with modifcations).
As seen here (taken by sirispj - Flickr.com):
Example: