To me, the requirement some seem have for IS on the 24-70 is somewhat difficult to understand and I wonder if it is based on real world experience or just theoretical thinking. When I first bought it, it replaced my 24-105 f4 IS as my standard walk-around lens, and I thought I would miss both the 70-105 range and IS. The truth is I don´t. I have a very low threshold for buying the latest and greatest, but I don´t see how IS on this lens would tempt me. Improved IQ would, but that will be quite difficult. Improved magnification, like the 24-70 f4 IS, would. But I am still able to hold my camera sufficiently still to get my shots also in low lights with this lens and I have other alternatives for macro. When IS would help, I always get something moving in the image anyway (experience from the 24-105), so it is ruined both with and without IS.
So, I have the 24-70 2.8L II, I am extremely happy with it and I am pretty confident that I will hang on to it after a potential release of an IS version.