Really?
Seems like a stupid thing to do.
Waste money on a high performance laptop then turn around and use it as a desktop.
Is the 680M worth the extra cost, I dunno, but I'd imagine with some vram overclocking you'd get a nice boost out of it and I'd imagine if someone was truly mobile they'd think the extra cost for the sheer amount of extended battery life each recharge would be well worth it in the end.
It did address your school situation where the longer battery life obtained through superior hardware allowed a Nvidia based laptop to fill both a desktop and laptop style role providing both cutting edge performance, and unopposed dominance in the battery life area.
You're one heck of a salesman though, I'm going to start looking into one of these cherry laptops.