One thing you can't do with a desktop or laptop is relax with it in an easy chair. There's trhe world of difference between using a computer and watching TV. When was the last time you watched TV from an office or dining chair?
TV is a 'lean-back' medium and now we have a lean-back computer. It's a big change to the way we interact with computing technology. - We've moved from lab coats to dressing gowns and it could have a effect. Will this lead to 'lean-back' presentations, music, etc or will it leasd to falling asleep with an ipad over your face?