Definitely updates on a Mac no problem (unless you're running an older OS of course)
It worked for me but the instructions were not exactly transparent. It wouldn't recognize my camera until I selected storage from the LCD and clicked OK. Then I was able to install without problem. I'm running the latest version of Lion.
I agree on the not so obvious upgrade instruction. If I didn't read this forum, I think I would make the same mistake by clicking the next button without reading the complete instruction and checking the camera screen.