Even if the quality is equivalent the new 24/28/35mm a price 5 times higher than the current 50 F1.8 would scare potential buyers and push them to Sigma.
Regardless of price, an IS lens can't push someone to buy a non IS lens.
These lenses are specifically made with IS for hybrid shooters/videographers. Non IS lenses are not an alternative.
I actually disagree. I have a friend who's super into video (shoots with a hacked GH2) and doesn't care about in-lens stabilization. If you're really serious about video you'll have your own stabilization rigs, which is partly why he wants to add a 60d and 50 1.8 to his kit.
It's similar to the argument about the 70d's LV focus. A lot of people said serious video shooters wouldn't use it. I think the same applies here, which is why a stabilized 50 1.8 at around 5x the cost of the previous generation doesn't make sense. Beginners don't have that kind of money to spend on a 50 (especially one that isn't 1.4).
So, who disagrees... you or your friend? =)
I agree regarding auto focus—I wouldn't touch that with today's standards. But IS is different.
First of all: for many DSLR video shooters, putting the camera on a rig is a fail right there. As a concept it's not wrong, but it might be highly desirable to shoot "rigless".
Plus, a rig typically excels in stabilizing the motion to the point where you might not need post stabilization, or where you end up with camera movement that can be fixed in post, to a degree.
But what IS does is that it removes the micro stutter that is impossible to fix in post. This can be beneficial even with a rig setup.
Now, the photography world has traditionally done well without IS on wideish primes. The reason we're seeing these lenses now is due to video.
I do a lot of video on a DSLR (on and off rig) and I would take IS on my Sigma 35mm 1.4 or 50 1.4 any day.
