Yeah, I was gonna make a comment about size too. Would you still call it a 'mobile computer' when the thing sits on a strap on your wrist? Granted you may be able to stream the video to external display (and other external i/o devices). But that's a whole different category of devices...
It's not a smartphone because when you log-on to a site like facebook, it doesn't show any *phone* symbol beside *8 hours ago via Facebook for iPhone*. lol