I just finished getting Tangent Space Normal and Spec Mapping working after a few days of frustrating bugs. Very happy tonight!
Success! I was able to write a full exporter for Blender 2.63 that exports the DEngine Static Mesh format. So far, the engine can load these models with textures for Diffuse color and material properties for Lambert-Phong lighting. Next step is to hook up loading Spec from a texture instead of a straight color per material. Then Normal Mapping.