Would be nice if some real world rules could be used in terrain generation. For example anything over X height has a 50% chance of generating snow. Or have a setting of X distance from the map origin in the N and S directions starts to increase the % chance of snow terrain. With the X settings being set by the admin on map creation.
Also the ability to have a finite world, so again the admin will be able to set that the world can't be any bigger than X by Y and at the boundaries the world wraps around.
But overall, I'm liking the look of having the different terrain - that said you think he could have turned off day/night while making the damn video.