There's tilesets, but honestly I think they detract. My extended ASCII are like 8x12 pixels and scan really easily. Even at 32x32 I can't reliably tell the difference between a dog a cat or a rat in most tilesets, especially on first glance, so a lot of memorization is still required with tiles, they allow for less information to be displayed at once, and they are more complicated to recognize.
I agree, it is a proof that content >> presentation, but there's no doubt a better interface and graphics wouldn't benefit DF greatly -- it currently has a huge cost barrier before the fun part, which most people just aren't willing to try and break.