Yeah. Only thing I was thinking of taking advantage of the 3Dness was the moving about in the levels. The part that's currently pseudo-3D. Personally, I think it's mighty fine if someone can make their own unique design by making some low res pics in some fairly basic paint program, rather than having to be able to model things and such. Part of the reason why I'd really like to see it go OpenGL is so that things get simpler for the ones just making designs -- set up their own viewport and use/make regular wall textures and get a resolution-independent game. Adding creature models and such, OTOH, makes it harder (unless they just want to use premade content).
Like you said tho, you can still take advantage of going OpenGL in the fights without requiring modelling and such, eg. by rendering the level as a flat plane in 3D, letting you rotate it and such. And using OpenGL for 2D still has the advantage of being rather resolution-independent (both as the size of the images you're using and the screen-/window-resolution is concerned)
