I just sent back my 2nd lite, since launch. The 2nd was only 3 weeks old. I treated both like they were eggs.
My son who bought one at launch too, carries his in his school bag, has dropped it etc, has never had a hinge crack.
This second time, I phoned CS, they said now no longer consider the hinge crack a manufacturing defect, but misuse. I really had to plead my case with him. Just be warned.
I don't know how they could consider it misuse, when it seems that it is almost random when it happens.
I love my DS, but is nowhere near as robust as any of the other Nintendo handhelds. My GBA SP fell down an escalator, and was fine.
Aaahhh, the beauty of Chinese manufacturing.
~S