It happened to me about 5 or 6 times already and had to unplug it. Hopefully its not hardware related but I heard that Nintendo will be releasing an update to fix this problem just not sure when that will be.
I got NSMBU and Nintendoland. Want Nano Assault Neo, Tekken Tag, maybe Trine 2 and Scribblenauts. Next year cant wait for Pikmin 3, Wonderful 101, Rayman Legends and Aliens Colonial Marines.