A 50mm prime lens is an essential tool in almost any photographer's bag and various Canon EF 50mm f/1.4 lenses have been in my bag for almost twenty years. It is small, fast and moderately priced yet it gives an excellent performance, especially compared to the much more expensive EF 50mm f/1.2L lens.
However, the recent introduction of Canon's newer generation of non "L" lenses, like the EF 24mm f/2.8 IS, the EF 28mm f/2.8 IS and the EF 35mm f/2 IS lenses have upped the ante for the aged EF 50mm f/1.4 lens.
These newer lenses all come with IS, improved optics and coatings. The next generation EF 50mm f/1.4 lens will share these same technologies and come with the much sought after IS capability. The only fly-in-the-ointment will be the price. Currently, the EF 50mm f/1.4 can be bought for less than $350. The new model will probably cost about $800 and should be announced sometime in the first half of 2013.