Okay, these are obviously screen captures of some sort of opening cutscene, which is why I'm sick of people over thinking Mario, Kirby, and the Halberd. ALL of the starter characters could be seen in the opening cutscene of Melee. If there are only three starter characters, I'll murder my Wii. Mario is in these pictures because he's nintendo's mascot. kirby is in these pictures because his franchise was created by Sakurai. Meta Knight is in these pictures because he's a new character, not because he's a "savior". He was also the first New Character to appear in the original trailer. Mario and Kirby will not be the only playable characters in story mode. The purple guy is probably a minion of the hands or a new badguy (Lets hope he's a minion, cuz he looks way too cutesy to be the main villain), and they're probably POed at ALL the characters, not just Kirby and Mario. And sorry Stryks, but even if Black Shadow is in this, he won't be the main badguy. If they use an existing Nintendo character for the main badguy, it'll be Bowser again.
Ok, now that I'm done venting, here are my theories. Each character may have their own story mode, just like most conventional fighters, or their may be no story at all, just like adventure mode in SSBB. (Hell, at least there is a reason they're fighting now.) If they do adventure mode again, I'm pulling for co-op, and also ten times as many platforming stages as melee. The story mode will end in some 1 on 1 clash with a badguy, whether its Bowser, the Hands, some new dude, or each character's personal rival. This new post is awesome, but when I hear theories like "Black Shadow is the main villain" or "Meta Knight is the savior", because the point of smash is that no one franchise takes priority over another.
Except of course, for Mario...