I hope this theory hasn't been proposed but here's my theory of the playable characters of Smash. This could be obtained with the new information given in Brawl that some stickers can only imbibe it's powers to certain PCs. The first pic that we obtained is one from DOJO itself. It shows that the cellphone could only imbibe its powers to three characters: Kirby, Meta Knight and King Dedede. All of which are from the same world, World 4 or the Kirby series. All right so here's the picture as evidence:
And then, we get the major spoiler that this also confirms the playability of Ness, Jigglypuff and Lucario. Now, the pictures found in that original video is original game footage. None of it is edited because if it was, we wouldn't have seen the three. But looking how character-specific power-ups go, they can only go to PCs of the same world. You will find Lucario and Jigglypuff with Pikachu and Pokémon Trainer and Ness with Lucas. Here's the video link (4:20 confirms them):
http://youtube.com/watch?v=pfb2l-iYlRoAnd again, I'm using photoshop to clearly show you the evidence of their existence. I know the past thread uses the emphasized ones but I took it upon myself to use the same technique as above.
My pictures aren't as clear due to the fact I got this from youtube and these ones were from the Japanese Wii website so I'll put the ones on the other thread as well.


Now when you chose the cellphone, a Kirby series sticker, Kirby series characters got it. When you chose the Groudon sticker, a pokémon sticker, Pokémon series characters got it. When you chose the Lucas sticker, a Mother series sticker, Mother series characters got it. And when you chose the Sonic sticker, only Sonic got it.
Now what are it's implications?
1. Stickers are SERIES-specific
> They go for the series that the special stickers come from. A Lucas sticker can be used to power-up both Ness and Lucas while a Sonic sticker can only power-up Sonic. This proves that even if the sticker is of a certain PC, the sticker goes to the series.
a. All the characters shown in the special sticker are all the PCs in Brawl.
> Now this is somewhat still in the air as we don't know the status of starters and hiddens. But if tradition takes its course, Jigglypuff will be a hidden character. If I'm not mistaken, that would mean all the characters shown in that video has all the PCs unlocked. Therefore, the stickers we saw there are the final characters they can give power-ups to. Thus we have another follow-up corollary.
i. Sonic is the ONLY character in world 20; Pikachu, Pokémon Trainer, Lucario and Jigglypuff are the ONLY characters in world 8 AND Ness and Lucas are the only characters for world 7.
ii. Claus and Pichu aren't playable characters.
iii. Many fake rosters are now DISPROVED
OK...so maybe there's no bullet 2 and b...bad way of showing things. Anyways, I think you guys get the point. As for Kirby, Meta Knight and King Dedede, well I wouldn't know for sure. This was shown in the DOJO and it could have been edited.
I'm retracting Mewtwo from this theory and putting Pichu. It is now obvious that Pichu will get the cut. But this for me is still a bit of speculation. As for Mewtwo, I forgot that these stickers DO pertain to the PCs of SSE only. We all know Wario and Bowser aren't PCs in the SSE and most likely wouldn't have a sticker. So if Mewtwo were to play a villainous role in SSE then that could still mean Mewtwo's still might be a PC in multiplayer. Also, if it is proven that villainous characters ALSO are PCs in the SSE then Mewtwo goes back up in the non-playable character list. However, if it is proven that Lucario and Jigglypuff aren't starters, this theory is debunked. I'm glad I cleared that.