Sorry, I can't believe the aluminum body. There are too many antennas in this thing to allow them to do that. Look at the size of the antenna cover on the first iPhone...this one has to stay plastic.
We'll know come Tuesday, though. At least I think so. With the Pre release imminent...I could see them releasing a new iPhone within a month or two.
See this is where I don't understand the argument against aluminum. If this is true, then how do the MB & MBP operate. Some may say, 'Well they have a screen and keyboard that the signal can go through.' So does the iPhone. I'm not trying to argue, but I think they may be able to rework aluminum into the design without interfering with signal that much.
Just my 2cents.