Have I been waiting....no. I've been using the 24-70 II and it is remarkable. Plus, for what I use the lens for, my best shots either come from a tripod (landscapes) or with fast enough shutter speeds (people) IS is not needed, so, for my shooting, I really do not see IS as all that necessary. It would sometimes be useful, sure/maybe. For me, I am getting a long just fine without it. As another example, I really do not use the IS on my 16-35 f/4 IS. But, IS on telephoto lenses is absolutely used and much appreciated.
I did some searching and found these rumors from September 2018 and April 2019, so there's still hope! And if a 1DX Mark III is still rumored then the EF mount isn't completely dead and gone yet.
I had a 24-70 f2.8L II and it took great photos! But I didn't like the omission of IS for Video. It was rumored long ago that there would be an IS update to version II and so I sold the lens years ago, thinking an IS version wouldn't be far away and the second hand price would drop afterwards...
This wasn't smart. I now remember how long it took to get an update to the original 100-400mm lens.
I am an amateur with far too much $$ invested in EF to want to upgrade to the RF mount, I would very much like to see an EF 24-70 F2.8L IS!
After five next to useless EF 24-70 f/2.8 MkI zooms, I was onto the MkII as soon as it shipped. It's been 110% brilliant in every respect, worked hard for years with almost daily use. As I don't have the worlds steadiest hands, IS is something I tend to tick the box for when it's available, but I'm not going to hold my breath for an EF 24-70 f/2.8 IS. RF is the long term future, and R bodies with IBIS can't be too far away.
My fun and travel camera is a very cool little Panasonic G9. With stabilized lenses you get extremely useful Dual IS when combined with the G9's IBIS. It's a pretty awesome arrangement, no doubt coming to Canon early in the next decade. Can't wait!
It would certainly be nice. That said, I have gotten used to dealing with the non-IS version, and in most use cases IS would be of little to no help unfortunately (candids).
I always said to myself that the day a stabilized EF 24-70 2.8 hits the streets, if the optics held up I’d trade in both the non-IS version and the f4 version to get it. It’s the ultimate walk around lens as long as reach is not a necessity.
The other possibility is that IBIS gets put into a future DSLR, which would be great as well.
This is such a standard pro lens that I can't understand why they don't have IS. The (highly rated) Tamron G2 and Sigma Art versions have it, the latest Nikon has it, other brands have stabilization in camera I think? Canon is the only one without. I had the f4 version partly because it did have IS. However I recently sold all my Canon gear and switched to Nikon D850 and now happily have a Nikon 24-70 f2.8 with stabilization (errr vibration reduction).