I'll be so pissed off if these Google Glasses can't interact with the iPhone just because Apple and Google are pissed off at each other... Those look great. Even just as a dumb display for my iPhone with some simple touchpad gestures on the side, I'd buy one.
What happens depends on what interests Google more: driving the spread of Android through less-than-fully-aligned carriers, or gathering the data that everyone using these with iOS could provide. I'm guessing the latter.
Apple may respond not by blocking a fantastic bit of kit (which would infuriate customers) but by buying a company that has its own patents on similar technology and building on the play they made in buying C3 from Saab. I'm hoping the latter.
I can't remember where I read it but one journalist wrote something along the lines of "how Google Glass looks doesn't matter - that's nothing that a partnership with Armani won't fix". Whoever they were, they were right. I just hope that Google partners up with a variety of brands to make a number of different designs.
Anyway, no matter what they look like I will be there on day one. I don't normally subscribe immediately to new tech like this. Took me a year or two to get a smartphone and I still don't have a tablet, but Glass is different.
One more thing - I really, really hope that people will find a way to load new OSes onto Glass. The technology is fantastic but it won't reach its full potential if it's locked away.
Splitting a PCB like that is really hard, electrically. Board level signals aren't designed to be run in parallel cables. At best you'd probably just put the battery on one side and the board on the other.
Sitting on a thin wallet day after day can screw up your spine alignment. Wearing a CPAP oxygen mask (for sleep apnea) night after night can shift the alignment of your teeth. If there's any weight to Google Glass at all, I imagine wearing this day after day could eventually have negative effects too.
I would probably aim to have it very gently hold on to the sides of your head, rather than simply sitting on the ear. I think that by spreading it out across the bridge of the nose, the tops of the ears, and the sides of the head, you could keep the pressure pretty low. I'd be most concerned about the battery--it's heavy, and may tend to get hot.
Maybe it's to counterweigh the camera at the other end? (and in addition provide power, as indicated below). Without a counterweight (or something to stabilize it) the "glasses" could rest a bit unstably on the nose with the camera and display. Of course a strap would also work, but then you would need that remote battery pack mentioned in the comments.