I don't have the thinnest laptop in the world. If anything it's quite chunky and quite sturdy, with the exception of the 180° rotating screen, but even then it's a hearty bit of kit. My BlackBerry is wide and deep in size, fitting my hand quite nicely and the keys are big enough to tap away on quite comfortably.
But I only really noticed this today in comparison with other devices. The fashion at the moment seems to be "the thinner, the better", as if we would starve our technology in vain effort to slim them down. It's like this crazed fashion stint we have at the moment is focusing on "size zero technology".
But for some, strange reason, if I was to be given one, the first thing I would do is stress test it: I'd flip open the phone and push the screen back and see how far I could stress it before it snaps. Perhaps it's a standard "want" to do; if something seems flimsy or so thin it could break easily, I'd be tempted to give it a go.
Ultra-thin devices like these do seem to be a trend that is spiraling forward and sees no sign of subsiding. But if you were to look at other progressions in technology:
Mobile phones started out huge, then got smaller, then got slightly bigger and thicker - where they seem to have stayed.
Televisions started out with small screens but huge in design, then the screens matched the size of the design, and now the bigger they are the better they are.
Laptops were initially small but chunky, and now they're thinner and wider.
Maybe through time, the "size zero" phase will wear off. There may be a time where consumers (and therefore manufacturers) will realise that devices need to fit quite a bit of stuff in there. With the MacBook Air, it lacked FireWire and an optical disk drive because they would have thickened out the laptop too much.
I've never seen anyone with a MacBook Air. Perhaps those considering buying one realised the importance of an internal optical drive.
My personal opinion? I'd say try and make devices proportionate, but don't aim for a specific thin design. Fit everything else you can in there first, and then figure out if you can slim it down a bit.
I don't like my partners to be stick thin. I like a bit of chunk on them, along with the vast majority of English men. Just as technology should be; you know, something that you can actually feel in your pocket, excuse the innuendo.