dregenthal
Veteran
While less important for slomo, it would be great for 24 fps (there's no 24p currently, but think that will change soon).
I'm not certain which you are referring to (the new Hero3 or the Hero2) but they both have 24p . . .
It's stated in the specs for the Hero3 and was delivered in the free software update you referenced.
I think a lot of people had a problem finding it (I know I did), you have to be in ProTune mode to access it.
Best.