IS may not be what you look for or need for your own particular usage, however for others (particularly those focussed on video, or who make significant usage of video) IS is a massive advantage in a lens.
as a still shooter this is something that i have come to understand despite not having any real experience shooting video.
my question is however, how useful is a mid range zoom for video? would a prime be more desirable at those focal ranges? i see plenty of 70-200mm 2.8 IS lenses being used by video guys on the weddings i shoot but they are always locked down on tripods/dollys and as far as i know the focal length is not being changed during filming.
i still contend for still shooting that IS is usually a bad solution for low light at wider focal lengths. i completely understand it for longer focal lengths in all lighting conditions but i think faster shutterspeeds at higher ISOs is always a better solution. IS cannot overcome the physics of motion in the scene below 1/60th of a sec. only faster shutterpeeds can and on occasion strobed light.