Nintendo service, at least in Australia, is pathetic, if not non-existant. Thats why im touchy on this topic. Ive already had to pay $55 AUD to repair my DS-Phat due to a crack in the circuit board on the touch screen that was not my fault (Anything to do with the touch screen not covered by warrenty, wear and tear item), plus wait 2 months for my gamecube to come back from repair (stuck eject button). Actually it never came back, K-Mart gave up with them and gave me a new one. This is now why I purchase all hardware from EB, who swap it on the spot and as they say "Let management deal with Nintendo (they have had problems to)".
This poor service is not an isolated incident, Nick wo writes for rev-europe sent his DS in with some stuck pixels, only to discover that the repair center "could not see them" and charged him $25 AUD for this. He sent it back with a diagram of where the pixels were in which case they admittred it, changed the screen and refunded the $25.
This poor service is one reason why Nintendo is doing poorly in Australia. Sony service is excellent (even though there hardware is not reliable) according to my friends, and my manager friend at EB states Microsoft service for the XBOX is also excellent here.
If you read the reports, you will find that once the crack gets large, the screen does not lock in place and some wobble. With that said I have no crack in my hinge whatsoever. I dont abuse it but I dont handle it with kid gloves.