It seems that a slip that was quickly corrected by Nintendo let slip three more playable Characters for Smash Bro's Brawl.

While watching the video the guys over at Gamefaq noticed the slip -

" While watching the video Gamefaqs forumites noticed that Jigglypuff, Ness and a newcomer Lucario will be playable in Smash Bros Brawl. The reasoning behind this is because in a part of the video where the sticker mechanics are being shown, the icons that show which characters support certain stickers show the Pokémon Lucario and Jigglypuff as well as Ness. "

http://www.n-europe.com/news.php?nid=11426