A fourth clip has rolled out from the upcoming Tron Legacy and unlike the previous three clips this one is set entirely within the real world rather than within the world of Tron. It's more a Legacy clip than a Tron clip, if you want to look at it that way, as it revolves mostly around Bruce Boxleitner's recurring role as Alan Bradley. You can check it out along with the previous three below.
Fresh Clip From TRON LEGACY