I got basic wall texturing working, and I mean really basic. Right now only the right side - middle texture is drawen and even then the texture coordinates are just plain 0 or 1, no calculations.
So there are lots of missing walls and messed up textures, but I still think the screenshots look cool.
DOOM 1, Level 1
DOOM 2, Level 31
Are you using OpenGL or Managed DX for this project?