Ah, right. Probably can do that, but not much point. It's less CPU intensive to keep it as it doesn't have to worry about regenerating those bits if/when they're needed. Meh, I don't really care -it's only 160MB!
I'm still thinking I should look into the hMod thing where you can put the world into a MySQL database for better performance and more reliable saves, but I'm not sure if you can move existing worlds to MySQL or if you have to create them in MySQL from scratch. :\