Please no. It's not that I wouldn't want IS on a lens, but what about the many customers Canon has that want a 50mm f/1.4 lens that don't want to spend $900+ for a non L lens. If Canon made a non IS & and IS version then awesome, but if I had to choose, i'd say give me IS on my zooms and no IS on my wide primes. Typically, if I am shooting landscapes or other non moving or slow moving objects to want IS, i'm not shooting at f/1.4 or shooting way wider than 50mm. Most of my 50mm f/1.4 work would be portraits. Other than detail shots at a wedding maybe, I have never wanted IS on a 50mm because my subject is always moving. I've longed for it on my 24-70 though since I use that for landscape style shots and love it on my 70-200 since at 200mm, IS is a must the way my hands shake. But on my 50mm, I want around 1/100th of a second shutter in almost all cases anyway that I use this lens for so who needs IS. I guess for video the 50mm IS would be awesome.
IS is great for handheld video, landscapes (or other still objects), and telephoto lenses. The 50mm f/1.4 doesn't really fit any of these except video.