I think this site causes more harm to third parties than Nintendo itself, and tend to agree with the idea that Nintendo wouldn't shut this place down.
I think at worst they'd put out a cease & desist of some sort as they did to a rom site with a forum, but they didn't even shut down the popular direct-download rom site with a forum that I can't mention specifically.
edit:
The site I'm referring to actually profited off hosting Nintendo's, and third party DS content along with some other platforms', by selling "extra bandwidth".
GBAtemp does nothing so direct that legal action could so easily be levied against.