According to Nintendo's statement, "A very small percentage of Wii consoles may have trouble consistently reading data off... [the disks used by Super Smash Bros. Brawl] if there is some contamination on the lens of the disc drive." Apparently, Nintendo is pointing to Brawl's high capacity disk format for causing the issue, but luckily Nintendo is offering to clean your Wii for free if you are experiencing the problem. Users that are facing this issue should
go to Nintendo's online form, fill out your information, and be prepared to mail your system in for maintenance. Nintendo has agreed to cover shipping costs, and the cleaning is free of charge; the up side is that those of you unlucky enough to be having the issue might find yourself with a cleaner Wii, as a result. The drawback is you won't have your Wii for a bit, and you'll have stare longingly that shiny new Super Smash Bros. disk instead of playing it - at least for a little while.