My Wii broke shortly after getting SSBB (on -the day- Spring Break started) and I was completely bummed. I called them up, they were amazingly nice and helpful, and I sent my Wii in. Got it back within 8 days.
The sad part is that I didn't have my Wii during my Spring Break, but the good news is Nintendo's customer service is top of the line.
Top of the line.