The good news is that I improved the SDL renderer and I get 170 fps on libtcod 1.4.0 (only a few hundred blits per frame for the first sample).
I'm currently working on the heightmap toolkit. This one won't have a sample but a standalone program to test it : the hmtool ! With it, you'll be able to design your terrain by hand and then get the code to rebuild it from scratch in your roguelike. It's far from being a professional terrain building tool, but it has some nifty features, like the rain erosion function :
Anyway, things are going pretty smoothly and libtcod 1.4.0 will probably be released during September, maybe with arena 0.8 !