I think te world record has to be WarioWare for the GBA..Its usually cool games that nintendo seem to take ages with...DS Trauma Center took 8 months from the US release to hit Pal land...Elite Beat Agents is an 8 Monther as well...As i remember Animal Crossing on the Cube holds the world record for time between NTSC and PAL...BUT none of those matter! Because the DS is region free and Freeloader for the cube made those waits not matter!
Its the worst thing about the wii right now is the lack of being able to play imports