Sorry for the pedantic comment, but the bokeh of the 1.8 is pentagonal (five-sided), not hexagonal (six-sided).
I do agree with the assessment that if Canon made a 1.4 with the build quality and wide-open image quality of the new 24mm, 28mm, and 35mm IS primes, the sales of the 1.2L would be greatly affected. I like my 1.8 v. I, but I'm always on the lookout for a deal on a used or broken 1.4 because of the wider aperture, better (not excellent, though) build quality, and USM (though not Ring-USM). Personally, I wouldn't consider the 1.2 for myself because of price alone, but the advantages over the 1.4 (build, weather sealing and Ring-USM) are obvious. The image quality and focus accuracy are debatable.