I know this doesn't help much as I'm not sure if there is a new version coming out soon, but currently it is a great lens. I purchased mine for $600 new and I don't regret it at all. I wish it had weather sealing but for the price I can't complain at all. It produces very sharp and contrasty images and I don't miss IS as I shoot outdoors and need a fast shutter speed to stop action. Honestly if they released a new version the price would surely go up and I wouldn't trade mine in for it any time soon. Hopefully this helps!
IMO, I don't think there will be a new version anytime soon because it's not badly in need of an upgrade. I purchased mines for $599 during the rebate and it has to be one of the best deals for a lens. It's razor sharp (even cropping it at 100%) and the AF is extremely fast, works best during daytime since its F4 and doesn't have IS. Any new release will be more expensive if there is improvements. I say buy it now and be happy.
It seems very unlikely they would replace this lens. With the IS version already the better newer lens, and the 70-300 f5.6 IS intruding on the saw space, it's more likely they will discontinue it flat out.
From what I have heard, it is well worth the money, and you should buy without worry.
If Canon introduced a replacement I’m not sure who would buy it unless they kept the price point about the same. At $600, the lens is nicely priced. But add $200-300 to the price tag and folks will just jump to the more advanced models. Canon could add weather sealing, but the IS version already exists. And, as an earlier post states, it’s a great lens.
Very unlikely. The IS version is the newest version. Canon was smart and kept the low cost non IS version, but updating it would make it cost as much or more than the IS version.