All right, I don't know if anyone cares at this point among these new rumors, but here is a stage analysis if there are 41 stages.
Let's see how many stages there could be per franchise, assuming every character gets their own stage (either individually or by sharing).
Smash Bros. - 2 (Battlefield and Final Destination)
Mario - 4 (Mario on Delfino Plaza, Peach and Bowser on Mario Circuit, Luigi on his stage, and a bonus Mario stage [preferably based on Paper Mario or Super Mario Galaxy])
Yoshi - 1 (Yoshi on Yoshi's Island)
Wario - 1 (Wario on Wario Ware)
Donkey Kong - 2 (Donkey Kong on Rumble Falls, Diddy Kong on his stage)
Zelda - 2 (Link, Zelda, and Ganondorf on Bridge of Eldin, Young Cel Link on his stage)
Kirby - 2 (Meta Knight on Halberd, Kirby/King Dedede on their stage)
Pokemon - 2 (Pokemon Trainer on Pokemon Stadium 2, Pikachu/Jigglypuff/Other Pokemon on their stage)
Star Fox - 2 (Fox on Lylat Cruise, Falco/Wolf on their stage)
Metroid - 2 (Samus on... apparently both stages. Aw man, are we sure Ridley is confirmed out?)
Mother - 1 (Lucas on New Pork City)
F-Zero - 1 (Captain Falcon on his stage)
Fire Emblem - 2 (Ike on Castle Siege, Marth on his stage)
Ice Climbers - 1 (Ice Climbers on The Summit)
Kid Icarus - 1 (Pit on Skyworld)
Animal Crossing - 1 (Possible AC character on this stage?)
Pikmin - 1 (Pikmin & Olimar on Distant Planet)
Game & Watch - 1 (Mr. Game & Watch on his stage)
DS - 1 (Pictochat as a level with no character)
Wii - 1 (I believe the unknown icon is the Wii symbol for this stage. The DS got a stage, so why not the Wii? Maybe this stage could be based on the Mii Channel or Wii Sports)
Sonic - 1 (Sonic on his stage)
Metal Gear Solid - 1 (Snake on Shadow Moses Island)
Classic - 8 (Hyrule Temple, Yoshi's Island, Rainbow Ride, Corneria, Brinstar, Onett, and two others)
Total - 41