Basically, the game is run through a formula to convert the output signal of the game from NTSC to PAL & PAL60 in the vast majority of cases. The rare exceptions like Metroid Prime 2 are when the game engine causes lots of bugs and the like by the timing issues of PAL, so it just got PAL60.
What makes this even more excruciatingly painful is that every PAL TV in the past 10 years or so can use PAL60 (Pal 60 Hz Mode) with the same refresh rate as NTSC (60Hz), as opposed to PAL (50Hz).
PAL is basically NTSC with colour correction and a higher resolution (I think NTSC has 480 vertical lines while PAL has 530 or something). Essentially PAL60 is superior to NTSC in every possible way, while PAL is superior in all ways except for 10Hz of refresh rate (Your eyes can barely distinguish above 30Hz, though).
Just to give you an idea of how absurd the whole thing is, this is all done by the console Hardware. Eg, if you have a PAL Gamecube, and use some method to play a Japanese or American Gamecube game, the PAL gamecube itself will actually output the game's signal in PAL. Likewise, an American Gamecube would always output NTSC. The only thing controlled by the game in that regard is the refresh rate (Eg, an American Cube playing a PAL game that doesn't have a PAL60 option would actually output the signal as NTSC50, which no TV sold in America or Japan actually support).
So basically, the only thing that's stopping Nintendo from releasing the game simultaneously in Australia to America is the 5 minutes to program the function of switching the output frequency to optionally 50 or 60Hz and changing the region coding of the game, plus making the suitable adjustments that will allow the game to use the correct region's firmware (Jpn, US and PAL Wiis have slightly different firmware).
