I've had the new 24mm f/2.8 IS lens in for about a week or so and have decided to give a few first impressions prior to a in-depth review (maybe not here, on this site, as lens reviewing is time consuming). At $849 or £749 (inc 20-percent VAT) this new lens and its sibling, the similarly priced 28mm f/2.8 IS, is not inexpensive*. Indeed, it is nearly twice the price of the old version. But that could be offset by the optical quality, or imaging aesthetic.
The beauty of this lens, of course, is the Image Stabilization (IS) option, which allowed this critically sharp image at f/8 using a handheld shutter-speed of just 1/40sec, lower than I would normally like even when using a 24mm wide-angle. The picture was taken with a Canon EOS 5D Mk III at ISO1250.
I'll reserve judgement on the optical quality for now until I've taken more images and performed my usual tests. Although this is pure speculation on my part, I don't think this lens was made for the EOS 5D Mk II or MK III (or the EOS 1D series either). Are we going to see a smaller, lighter, cheaper full-frame body in the near future? I think so.
* Also, bear in mind that the lens is delivered without a lens hood nor a soft case.