With the 360/PS3 I would get an extended warranty but with the Wii I dont think Id shell out the extra cash. I havent read a single bad thing about the Wii having any problems.
like you said elot, nintendo systems are very reliable, i still have all my nintendo systems like the SNES that works perfectly fine and just as good as it worked back when i was a little kid... so people shouldn't have to worry about any bugs/defects in the Wii, and even if there are some kind of defects, nintendo will take care of it by repairing it for you and such...
kinda like when the ds lites started cracking up, nintendo just repaired it for you... nintendo likes to take care of their customers