You may have to give in to the dark side (Sigma) to get you over the hump...
My Sigma 35mm has been rock solid despite the negative press. I assume the 50mm is the same kind of deal, if so it's definitely a good option. Maybe I got lucky, but I'm not sure why the 35mm and 50mm have such a bad rap. My 35 misses maybe one out of every thirty shots or so, which is about the same as my Canon lenses miss?
That Tamron 45mm seems really nice too. Then there was that new Tokina announced a few weeks ago. Lots of good manual focus options as well.
I want Canon to make a nice new middle-range 50mm, but I'm not too surprised they don't considering how many good options there are already. It's probably hard to make something which can compete with the Sigma and Tamron optically but without stepping on the toes of the 50mm f/1.2. Like, look how long it took for the 85mm f/1.4L IS to be made.