even if (when) canon releases a 14-24, i'll stick with this lens as my primary UWA.
24-35 is just too useful a range to give up w/o changing lenses, and i'm skeptical as to whether the new 14-24 would even have filter threads, or at least be a size matching the set i already own.
now if canon decided to release a mkIII (highly doubtful anytime in the near futuer) with improved corners at 2.8-5.6 and 35mm that wasn't soft in the center at 2.8, i would be overwhelmed with happiness
This lens does a great juggling act between image quality, versatility, and the limits of lens technology. That said, I agree that image quality was where the compromise was made with this lens. This lens has an incredible focal range, it's light, and it's reasonably priced for what you get. But it's not super sharp. And corners are often soft, distorted, and full of fringing.
Like many folks here, I would prefer a 14-24mm with improved IQ. That said, If I could have only two lenses, the 16-35mm would be high on that list.