I have to say, I'm actually really impressed by Smash 4's marketing. It's definitely the best I've seen for any game, ever. As an amateur designer, I'm pretty much deciding to buy both versions of Smash 4, and a Wii U, just on the principle of how genius their marketing has been these last 2 years (especially this year). And this doesn't just apply to Smash 4, but also the Nintendo Livestream event during E3. It's been absolutely amazing.
I'd just hate it if they squandered their brilliant marketing so close to the release of Smash 4 by not revealing Ridley officially. But I think it'd be even worse off if the Smash Team didn't include Ridley as a playable character at all. Idk, that's just my opinion, though. Either would be pretty bad.