I have not found any information other than "Fall 2010" on the opening of both Cantina (the QS) or Hacienda (the new TS). I have heard rumors of everything from Sept 15th through "in time for F&W", but until I hear either more consistent rumors from different sources, or actual word from Disney, I'll not put much stock in them.
The QS location will likely be opening right around the time the TS location opens, although it could be slightly earlier (if they finish it first and the kitchen/common areas are ready).