The patch contains various bugfixes and game improvements such as widescreen support, and provides some GUI tweaks. It also enables the use of the FMSel fan mission loader frontend with Thief 3 and bundles the most important T3 mods. It works with the GOG and Steam versions of the game.
A comparison of the flat frob hilight in MP before and after enabling third person. It was necessary to change it from using a shader to using textures instead, because the shader would affect 3rd person Garrett too.