You know, I'm honestly surprised that nobody has decided to make some sort of stupid comment about saying that there's going to be an amazing update for December 3rd's update.
Crap, I just said it, didn't I?
I believe there's truth to this theory, though. It isn't "HEY IT'S X IMPORTANT GUY'S BIRTHDAY!", or "HEY IT'S THE 150TH UPDATE".
This is actually a smash-relevant date, and he knows that. I think he'd bring something good to smooth over the day for people like me who'd be playing smash all day. He's not an idiot, yanno.
As for Melee stages, i think Pokemon Stadium is coming back, as PS2 is billed as, you know, Pokemon Stadium 2. Fountain of Dreams for Dedede, but redone. Same for Green Greens. I havent been impressed by any mario stage so far, so i think a Galaxy one would be sufficient. I think Final Destination is coming back, but i think it may be covered in the form of that Arena we saw in SE. (gameplay footage confirms about the same elevation/length, although not the same top-shape). Battlefield is already returning, but that doesn't count.
I dont think any of Samus's previous stages should make a return, because of the relatively bland nature of all of them. Any of Yoshi's stages making a return would make me happy, verily.