The final 1.1 version of Thief 3 Gold fixes the 'endgame bug' and several minor issues. Note that savegames from T3G 1.1 beta cannot be carried over.
If you are using the 188.8.131.52 standard edition, then this release can be skipped. Versions 1.1.4 and earlier should be updated, but note that 1.1.4.x does not work on Windows XP - will hopefully be fixed in the next release.
The SU Editor Edition has been uploaded here - a set of minor improvements for Thief 3 mappers, in addition to installing the patched game exe into the editor environment.