I would love to see a Bowser's Castle stage, particularly if it was given the Palutena's Temple treatment. A labyrinth full of Thwomps, Dry Bones and molten lava?! Count me in! On the other hand, if we got a Mario newcomer in Wart/Mamu (however unlikely that may be), Wart/Mamu's Throne Room would also suffice. Wart's Throne Room would be in disrepair, possibly ransacked by Subconians, so the roof would be gone. The background would be very ruin-porn-y, somewhat like Mushroomy Kingdom was in Brawl, but less barren and more jungle-esque. Think Abandoned By Disney. Poison Bubbles would eminate from The Dream Machine, popping on contact with fighters. They would not cause knockback, but would slowly damage them like the Lip's Stick. And... that's all I got. ALSO THE SPECIAL WORLD FROM SMW.