We have a video of Steve answering this very question. Clearly I wasn’t the only one that was curious.

He doesn’t just give a simple answer why and then try and move on either, the video is actually worth a watch. The summary is that the battery life for a 3G iPhone just isn’t good enough right now.

As a bonus I put a video prior to the event at the bottom of this article, it gives you a good idea of the number of people there and of the size and appearance of the Apple Store in London. So watch and enjoy.