I don't think anyone can vouch for being an interesting character in the Metroid series.I would be shaking my head at a Dark Samus inclusion. Dark Samus isn't even all that interesting of a character in the game she/it's in, Ganondorf is the main villain of the series and further more I don't think he should have been a clone of C Falcon to begin with.
I don't know about "outrage" but I can't imagine many people being hyped for dark blue version of Samus.
But if Dark Samus is so uninteresting, go with Metroid Prime. It's the final boss of one of the best games ever made and it has basically the same abilities anyway.
Prime's actually pretty small and could work constantly floating ala Mewtwo. It even has tentacles to hold onto items.I think Metroid Prime's final form would work more as a boss than a playable character, but that's just me.
The more I think about it, the more I like the idea. Final Smash would of course be the giant face crab.
That's only if Sakurai is astoundingly lazy... Like he was with Ganondorf.Anyways, Dark Samus wouldn't cause outrage at all and is not the equivalent of Cole and Evil Cole. It would be the equivalent of Toon Link and Link or Ganondorf and Captain Falcon.
So I think we can rest assured that Dark Samus will be a Captain Falcon clone.