I don't know if you're following all the news that's coming out about IP, Rflong, but I guess you can't place underwater lots in most other worlds because the sea level won't be deep enough for them. Don't know if you were planning to try to put any in your new world or not. According to what I have read, boats and docks and resorts etc., will work in any world though.
There is also supposed to be a lot adjuster feature that allows you to position your house anywhere on the lot when you plop it down. Is that not awesome, or what!??!