In another thread you asked about the 24mm F/1.4 II. If you get the 24mm you may have no use for the 16-35mm. I have both and hardly use the 16-35mm at all now. In fact the only time I have had it out in the last year was for video.

If you are adding to your kit, and upgrading you may want to take it a step at a time rather than upgrade to a lens you may be using even less.