Clearly you two have idea about the controversy surrounding Ridley. During the pre-Brawl days, there's been an argument on whether or not Ridley should be a playable characters. One side supports him because the Metroid series needed another rep, since we've got two variations of Samus as our only reps, and he's an iconic character like Mewtwo, having to the most recurring secondary character in the series. Another side is against him because he's "too big", which is an argument that's easily debunked because Smash Bros. never stays true to the characters' sizes *points to Bowser and Olimar*. Over the years, it became less about Metroid's status to warrant a newcomer and more about eliminating that "too big" argument once and for all. In the direct, we could see Ridley functioning like a playable character should, even having a character icon of his own, but for some reason, Sakurai didn't downsize him. I could say that he may eventually become playable via DLC, but my gut is telling me that Mewtwo will be the only DLC character because he's some sort of "special case."
Edit: @Zekrom: You can ignore this if you want, since you've already responded to my post at the Smash Bros. club.