If I compare my SAM-city here on Beta to my SAM-city on live, there´s some changes in layout in the "sea" or "lake" as well. Some rocks have been removed, and some have changed in appearance. I guess we´ll just have to see why. But some kind of future building seems quite likely.
What I´m more concerned about is where future city expansions is going to be placed. Sure, there´s still grids available, but if we´ll get 4 on average per new age, we do run out of city grid to expand in about 4-5 ages. I know we´re probably talking another 2-2½ yrs of gameplay, but we do run out nevertheless at some point. And I just wonder what the game designers will come up with when that time comes.