The Japanese website compares the iPad Pro to Microsoft’s Surface implying that the preferred method of use will be landscape instead of portrait which has been the default iPad orientation since its 2010 inception. Indeed, the iPad Pro is said to have stereo speakers on the top/bottom or left right depending on orientation. The iSight camera, Lightning connector, and Touch ID home button position will not change however.
As for the “all important” thickness, it is said to be somewhere between the current iPad Air 2/iPhone 6 and iPhone 6 Plus which would put it near 7mm.
Interestingly, this chassis is compared to the upcoming Quanta built MacBook Air which could in fact share the same exact retina display.