I see what you mean about the brown around the mountains. Frankly, I think if you can walk on it, it should be the color of the grass.
IMO, it looks like you guys might have went a bit overboard with sharpening filters...
My personal wish: I just wish the map wasn't so... flat. A bit more realistic topology would make things look a lot better. For example, hills should be... hills (areas where the terrain height differs/changes), not just some bumps on the map (seems like something from decades ago)... etc. I'm a bit surprised that you guys haven't done it with such a powerful terrain deformation system already in place.
You're thinking about the screenshot like it's a piece of art. That's fine, but keep in mind that LH is not art, it's a game. And the first consideration has to be that it's playable as a game.
The trees and mountains look like icons because they are icons. The icons describe their tile in an intuitive way. The old design obfuscated the borders between tiles, and it made some pretty pictures, but it resulted in a decrease of reliable information to the user.
Adding more topography to the game would be a beautiful change, but likely brings up whole new problems in because the user is using a 2D plane to interact in a 3D space. So now, behind your pretty map is an arduous struggle for the developer as he tries to prevent user's clicks from going astray.