Not sure if Apple will even do a 'iWatch' and even so if it will look like a traditional watch. Together with MacUser magazine in the UK I designed, modelled and rendered a possible iWatch. Later I added a colorful 'iWatch[C]' version.
More images on my website: http://www.martinhajek.com/portfolio/iwatchc/
The 3D model of the iWatch: http://www.turbosquid.com/FullPreview/Index.cfm/ID/775463?referral=MartinUtrecht