I picked up CD as my first WWG purchase, I'm having a blast building it.

I tend to use a lot of pre-published adventures, and most of the maps have the walls line up on the grid instead of centered in the squares. An altermate set of walls lined upon the grid would be great (I know I can kit-bash these using the existing walls on the 1.5"x3" and 3"x3" floor sections, but the intersections are going to get a little tricky).

Diagonal walls would be great, as would more curved walls of different radii.

As far as props go, I'd like to see fountains, small wells, raised platforms, alters, barrels, and individual treasure chests and crates.