Looking at the current Asus ROG 17" laptops, it looks like they've got a model that's only 7.5 pounds with a battery the same size as in the MacBook Air 13". Or you can get a 10.5 pound machine that's got a battery the size of what's in current 15" MacBook Pros and was in the 17" MBPs. And most of those manage to stay less than 2" thick, but they're all at least twice as thick as a current MBP. All in all, they've got almost as much in common with an iMac as with a MacBook Pro. (Seriously: the 21.5" iMac is only 2 pounds heavier.)

10 pounds of textbooks in a backpack is regarded as a public health problem. 10 pounds of computer cannot be taken seriously as something made for use on the go. We really do need some more specific terminology to draw distinctions between the different classes of hinged computers.