The following characters were revealed by a very unintentional leak on Nintendo's part. I will not describe the nature of the leak in this preamble, nor the characters that were revealed. Chances are, these characters were meant to be hidden, and as such will not be announced on the blog until well after Brawl comes out. If you're attempting to avoid finding out about such things, cease and desist.
That said, here is the relevant link. I'm also embedding the trailer below to fill space before I say anything.
You might have missed it, but hidden in that video were the unannounced characters. If you missed them you weren't alone, I certainly overlooked it (and apparently Nintendo did as well).
If you've read the link you'll know that the characters were Ness, Jigglypuff and Lucario (another pokemon).
So I both correctly and incorrectly predicted Ness, nailed the Puff, and am aghast at Lucario. I obviously don't pay attention to the Pokemon movies (phew). Sadly, chances are Mewtwo is out, which would be a black mark on my record.
My only major complaint is that there's over a month between the release in Japan and the release in America. As such, we'll probably know all the secret characters before we even get our hands on the game.
Accordingly, I'll cease to pay attention to any news outlets likely to reveal such facts, with the exception of the official page. That's unless the official page decides to have a blowout the day of release and crush my hopes and dreams.