I have the 24-70L to go with my 7D and yes, I'd very much like to have IS on it and 2.8 aperture.
The lens is capable of wonderfully sharp images, I'm not denying that, but unfortunately only in very good light (if handheld).
I am pixel-peeping here, since even though some say that 18Mp APS-C photos should be viewed at 1:2 to get an idea of the "sharpness", I always use 1:1. This is because I know that I can get (quite easily) sharp images with my 70-200L II when handheld, but not with the 24-70L. So it's either very good light or a tripod with this lens, which I don't like when this could be a good lens for photo-walks.
So if an image isn't sharp at 1:1 I usually bin it and that makes "keepers" few and far between with this lens. I'd also like to use IS instead of bumping the ISO since most of my subjects aren't moving.
There's also quite a bit of CA, distortion and the AF is inconsistent, so yeah, on top of the IS, I see a lot of improvements that could happen with the Mk II.