Hello,
I am programming a new 3d engine, and I was wondering if anybody had some suggestions.
Here is a list of current features:
.3ds file support, per-pixel shading, dynamic lighting, flat mirror texturing. All ideas are welcome!! 
Suggestion : google 3D engines, list all their features, and we’ll talk back in 4 years when you’ll have them all running. I think at this point, you won’t need any suggestions.
Actually it all depends on what you intend to do with your engine.
SeskaPeel.