I almost forgot this project.

See. It's able to import tilesets:
mapedit1.jpg
As you see, the import dialog is simpler than TileStudio's one. Also it uses Allegro.pas internally. This limits it a bit but I'm used to the API. Once everything works I see how to use a better graphics lib (i.e. Vampyre).

I'm having some issues with the PaintBoxes. When I change the width/height of tiles, the tile sample is re-rendered over the actual sample tile. Don't know why.