I think for the price, this is a great starter lens. The optics on the kit lens now aren't bad at all, only the build quality and AF speed are sub-par, which is understandable for a lens in this price range. If you add IS to those optics (and they supposedly have upgraded the optics a bit) and still offer it in that price range it is a fantastic start.
I figure you will see this lens in the box with the camera bodies before Christmas in order to kill the marketing push of the in-body IS cameras like the Sony and Olympus models.
As for it being a replacement to the kit if you already have the kit... I wouldn't spend the money. I'd sooner spend the extra hundred and change and get something like the Sigma 17-70 or Tamron 28-75 and have a much better lens optically and build-quality wise. Of course, that is if you are seriously learning how to take pictures. If all you are doing is putting the camera in green box mode and popping up the flash and clicking away, the IS might be a bigger help than the better lens.
