As I read it 'become the norm' implies that a majority of titles will have motion controls in some form at some point in the future - doesn't rule out in conjunction with other peripherals (because despite MS 'no controller' stance I'm sure they will use Natal with a controller too) and it doesn't imply it will be used where it clearly doesn't fit.
Also, not to be too cynical, but the use of future tense is a nice PR way of making some statements that can never come back to haunt you - I notice he never really said anything concrete about anything, really.
Personally I don't care if it's motion control, or not, or a mix so long as it works well. What I don't want to see (as the man himself says) is motion controls forced into games for the sake of it - something Sony tried with the Sixaxis which saw various useless implementations of motion controls within games that didn't need it.
Try to be reasonable... its easier than you think...
