I certainly hope that all the land textures get some polish before release.
They really do look like they're made of plastic - and I really dislike the way the rivers just look like water poured into a crease in the plastic. Rivers erode their way through the land, they don't just fill premade dents.
I'm sure all this stuff is going to be improved though, because if you look at the river closely you can see the road going under the water for example.