[flamerz]

I found that my DS got looser and looser to wobble as you've described it for the longer I had it and the more I used it. The sudden change is definitely a result of the drop, though. You may be able to tighten it yourself. I don't have a DS anymore, but if you're able to take it apart a bit, you may be able to see what's wrong with it inside the casing.

 

[Dachink]

the hinge is probably loose. You can send it in for repair if it starts to bug you.