The GameShark deals primarily with antialiasing, while the Ultra HDMI does a good job of removing secondary blur from 3D graphics.
While an Ultra HDMI cable does a good job of approximating a clean, pixelated look, the crew over at AssemblerGames.com, has discovered that sometimes all it takes is a GameShark to remove antialiasing on 3D graphics.
The guys over at My Life In Gaming have talked about a solution of sorts.