Piranha,
Your desert definitions are exactly the same as the DLR ones. And this is great news.
Now we just need some unit(s) with desert abilities (Mummies/Giant Scorpions/Djinn/Phoenix...) to take advantage of the new terrain in terms of a move bonus/terrain bonus/stack bonus in that terrain etc.
I am curious about one thing with the new model. Will it be possible for example to place a castle on a hill. Or must a castle always sit on open terrain? In DLR for example you could create a large hilly area (say 10x10=100 squares) and place a castle in the middle of that hill area and it would be a castle on a hill in terms of terrain so that units will hill terrain bonus got those when fighting in the city. Or will you have to just create a 2x2 open area in the middle of the hilly area to place the city.
KGB