Update 6:28 AM: Here is a slightly higher resolution version of the drawings, showing the smaller model to measure what appears to be 137x66 mm and 7.0 mm thick. The larger model appears to be 157x77 mm and just 6.7 mm thick, with that thinner body requiring that that the rear camera protrude somewhat as on the current iPod touch.
Urrgghhh....the current 5S it 7.6mm. There's no need to make it thinner, if the battery life is only marginally better due to them making it another 8% and 12% thinner my jimmy's are gonna be rustled. Keep it the same and jam as much juice in that bad boy as possible!