I really hope they don't take too long to make the story mode. People just play the story mode to unlock all the characters, that's all. I doubt anyone replayed subspace numerous times. Everyone spends their time with multiplayer, which is what the developers should really focus on. I think a cast of 50 characters (with no clones) would be perfect. If they are going to include clones again then they should just have that character as an alternate costume for another character or something like that. For example, Falco and Wolf would be alts for Fox. Also, I hope 3rd party characters are extremely limited and they only have one per franchise, maybe even one per company...
Also hope they get rid of random tripping over the air and make it so guns, blasts, lasers, etc. don't just stop in the middle of no where for some reason. Also, they should include a much more detailed stage builder.
I'm also worried about how we will be playing this game 5 years down the line. We won't be able to use GC controllers and I hated using the wiimote, wiimote+ nunchuck, and Classic controller as alternatives. Sure, I could play with them if I had to, but it was so much more simple with the GC controller. I just hope they release a new slim waverbird controller that works with Wii U games and that developers can chose to use as well for multiplayer games. I know this makes three possible controllers (4 with classic) but it is seriously needed if we only can have one Upad per U console.
Characters I would like to see included:
Mewtwo: I hated that they took him out in Brawl, kick Lucario out if need be.
Megaman: I don't think there is any other 3rd party character more deserving.
Bowser Jr.: He could have a pretty unique move set with his paintbrush.
King K. Rool: We need more "bigger" characters.
Little Mac: Also could have a pretty unique move set.
Ridley: I know everyone says he would be way too big. However, we have seen how big Bowser was in Sunshine and in other games. Charizard is supposed to be bigger than what he is in Brawl... If they can be shrunk down then Ridley can be shrunk down as well.
Midna: Could be a very unique character.
Samurai Guru: We need another F Zero character in the game.
Toad: I know there are already a lot of Mario characters, but we need Toad. lol
Krystal: Would be completely different from Fox/Falco/Wolf and be a very unique character.
Scizor: I know we have enough Pokemon and they would probably include a new one as opposed to an older one, but Scizor would be very cool to have as a playable character.
Goku: I know he would never make it in and wouldn't even fit in with everything else. But it would be interesting to play as him, to say the least.