Canon has however added IS to a couple of its popular wide-angle prime lenses: The EF 24mm F/2.8 and the EF 28mm F/2.8. Canon claims they'll combat motion blur by four stops. Both use new aspherical lens elements and have seven-blade circular diaphragms for smooth blur. They also both have Ultra-Silent Motors, so you can use AF during video if you so choose.
The 28mm F/2.8 IS USM will cost $799. Both lenses will be out in June, so we'll be interested to see how much of an improvement these offer in image quality, since the addition of IS makes them substantially more expensive than the old versions.