BWIA is a GREAT airline. Really, truly. It has a very warm and caring yet professional approach to flying. Its service is top-notch on the ground and in the air. It above all makes safety its number 1 priority. It would rather ground a plane for several hours to ensure that it is fully safe to fly than take any chances. As a result of that approach it has never had an accident in its 60 years of flying. With its new paint scheme and new 737-800s it is well-set for the future.
As for the TriStars, BWIA has been considering the 767-300/400 as a replacement, although I see posts in this forum stating that they are also considering the Airbus A330. I think that with their new 737NGs they would stick with Boeing for the sake of commonality.
BWIA's present fleet includes 4 Lockheed L-1011-500 TriStars, 5 MD83, 3 of 6 737-800s and 3 Dash 8 Q300s.