@bluebirde it is a little misleading statement but there is something to it.... the original spintires came with 5 maps and a 6th map was added in an update (floodzone i believe). So that new map they are talking about is Deluge.
This is kind of what i made out of the whole thing but i could be wrong.
This has been posted before in other threads but no official or conclusive answer has been given.
Hope this helps