First of all, Daisy should be in Brawl, instead of just as a Peach coloring. She has a whole different personality than Peach, and since Luigi is in SSB then why can't Daisy be? She should NOT be able to float, though... That's Peach's thing.
Daisy should be in and not be a clone, but Rosalina has a good chance due to SMG, and if she's in it SMG2.
And the 3D thing doesn't seem to appealing...
No, it doesn't.
NO MORE Sonic characters. They DO need Dark Samus, though, and make Zero Suit changeable like Zelda so I can play her in tournament mode ;.; Just get rid of her up B and make her down B her new up B. Sorry if that sounds totally noobish but I can't remember the non-noob terms for those moves.
I'd like to see Eggman, or another SEGA character if they have to add one in. Needing Dark Samus is like needing a punch to the face.
They also need to have WAY more stages. There were probably 7 stages that I really liked in Brawl (but I liked almost every one in Melee (except Rainbow Cruise... Grrrrrrr)), and two were Battlefield and FD, if you know what I mean. I liked Stage Builder, but they didn't have a big enough variety of parts imo.
There should be more crazy stages. Screw tournament legal stages, Nintendo should make more frantic stages to appeal to their target audience. I like neutral stages, but the game shouldn't be full of them.
There needs to be less instakill items, and NO smash ball. I always have smash ball off because it's just totally random and annoying, just like the 3 kirby machine part things (I forget the name right now). I like the hammer, though c: It's classic.
lol Fox/Falco 3-stock Final Destination.
However, whilst there aren't really any instant kill items as such, as most can be avoided, I believe there should be more of a variety. Smash Balls should stay, because I could see Nintendo adding them in as an actual meter that raises as you go through a match (similar to the Tension Gauge from Guilty Gear X) that you can't turn off.
OMG THEY NEED AN ANIMAL CROSSING CHARACTER. They could use their fishing rod, net, axe, and shovel to play, and as a projecile throw Bells at people XDD Their net could grab people, their fishing rod could, like, hook them or something, their axe could be a good smash weapon, and their shovel could maybe dig a hole so they could hide, or dig up dirt and make people trip or something. IT WOULD BE KYEWEL :DDDDD
Animal Crosser is generic, like a Mii. Someone like K.K or Tom Nook would be better. That being said, I believe Animal Crosser and a Mii have a good chance of being in the next game. Especially since the Mii has been in the Mario and Sonic games, Mario Kart Wii, and possibly Super Sluggers (but it's not out in the UK yet so I'm not sure.)