Ask HN: Ergonomics of touch screen laptops

Touch screen laptops are all the rage these days and I have seen a lot of people desiring the same for Macbook and OSX. But after thinking about this it seems that touch screen is very bad for ergonomics. You can't "work" on these things, it will screw up your shoulders and neck. Have anybody used touch screen laptops for day to day work i.e working for long period. What has been your experience? We need to come up with new HCI that puts ergonomics at the top of the list.