From nintendowiifanboy.com:



"Turns out, some have already found a pretty big glitch in Super Smash Bros. Brawl. While we'll say it involves a certain character (not the one pictured above) on a certain stage, we won't ruin anything else for you. Those looking to stay pure from all of the spoilers that are on the net for Super Smash Bros. Brawl might want to avoid the area past the break.

You've been warned."

Read about it at Super Glitch Bros. Brawl - Nintendo Wii Fanboy