I don't understand why this is such a breakthrough. Canon EOS Utility allows computer control of most recent Canon dSLRs. This iPhone app requires the camera to be physically connected to the computer (just as EOS Utility does), so the only advantage it offers is that you can step away from the computer, which could be useful for taking full length self portraits without relying on a timer. Pretty much pointless, unless you're a narcissist.
EDIT:
A real breakthrough iPhone dSLR control thingy would be a small WIFI transmitter/receiver that would plug into the mini USB port on the camera and would communicate with the iPhone. Short of this, anything else is just a waste of money.
