They were made using Granny, good luck, nobody has been able to change the 3D map themselves (though map assets like tower / flags / shop locations are easy enough to move around)
Yeah - this. One of the major problems to modding folks was the choice to use granny. We saw some really cool map suggestions and mods here, but that was not something they could provide us with via a mod kit or anything. You need the software which is priced really high. We had some really good looking maps imo anyway...
A bunch of us were super pumped up at one point to create new maps but we couldn't come up with something via SD or GPG. So yeah... new maps kind of bit the dust. And the creation of new maps wasn't deemed worth the investment. The game pretty much became about cataract, the population dwindled, so investing $$ in a new map didn't make much sense, really - even as DLC. Or that was the take at the time. Once DG hit steam, they probably could have easily justified a map DLC.
edit - heh - now I'm necroing threads also... ><