I know what you mean, Yesac13. I used to be one that thought that IS wasn't necessary at these shorter focal lengths - and truthfully, most of the time, it is not. But since I got my 24-105 a few days ago, and with the 28-135 I previously had, I'm finding that I am using IS quite a bit for just the kinds of shots that you mention. Last night, I shot one of those 1/20 second ISO 3200 shots at 99 mm focal length with the 24-105. My odds of getting a good, sharp result at those shutter speeds have gone up considerably with the IS.
If Canon can make a 24-70 f/2.8 IS that retains the smooth bokeh and functionality of the present 24-70 (and perhaps improves corner performance at the wide end at f/2.8), I will probably buy it. Maybe not in the first few months, but eventually.