I have the Dvorak keyboard layout and this issue affects me too. FWIW, Mac OS X 10.8.2, Java 7, MC 1.4.5.
It's frustrating and reduces my desire to keep playing to know that every time I have to switch my keyboard layout since keybinding wasn't made flexible enough to accommodate non QWERTY keyboards. I've automated the keyboard layout switching but it's still something I have to initiate before play.
I agree, this issue should be reopened as it has yet to be resolved by the default installation. Is there a way for this issue to be put on "hold" until the problem is fixed in the default download from Mojang?