I got the current Autoweek with the 2008 Challenegr on the cover but they don't give any real specs on the car size wise, just the wheel base, of which I've forgotten, I think 116", I'm not sure. They did mention that it has the 6.1 liter Hemi but the 6.4 liter Hemi maybe an option.
My friend gets subcriptions to Road and Track and Car and Driver and says he's already received the Challenger issues. Those should be on the news stands very soon and I would think will include lots more detail on the car.