it'd be kinda weird chopping off MK, he was one of the "hype" characters in the trailer for brawl wasn't he? and hes a pretty popular Kirby character....
anyway for me, cut priority goes like this:
1. snake
2. pokemon trainer
3. toonlink
4. sonic
5. lucario
6. ike
heres my reasoning. Warning! this post contains "IMO"
(deep breath)
Snake: 1st off, hes a 3rd party character, so he's already in the red. 2nd, he attacks waaay too fast for the third heaviest character making him sort'a OP imo. 3rd, the xbox 1 is hosting his next game, so maybe his focus will stay with Microsoft. I think if theres going to be another 3rd party rep, snake will be removed in favor of it.
Pokémon trainer: ok, so im kinda mix about PT, but its mainly because squirtle and charizard could have been made a lot better since they remind me too much of Mario and bowser,but on no account are they clones. I actually love ivysaur a lot more than both squirtle or charizard despite lots of others thinking the opposite. the whole "fatigue" status was also a huge bummer. also I think PT can be swapped for either a different pokemon, or a PT with different pokemon.
toonlink: not an EXACT clone of link, but hes way too similar. he either needs to have a different moveset entirely, or be swapped out for a different type of link. nothing less.
Sonic: again, a 3rd party character, BUT that's the only reason really. hes one of the lowest on my cut list because I believe a lot of people still want sonic in the next smash bros, the sonic franchise has been doing very well on Nintendo consoles, and Nintendo fans are warming up to sonic. sonic had a unique moveset that unfortunately ended up being bad do to its low KO potential, but this can be altered by tweaking him a bit and he'd be good to go.
Lucario: a have a bad feeling about lucario too, but I believe he can still make it. he gets blamed for stealing mewtwo's spot which is not true. mewtwo wasn't in do to time restrictions. there are many who play lucario simply for the fact that they loved to play mewtwo in melee, and lucario is as close as it gets. hopefully they will not cut lucario since he has an original moveset, but im thinking they need to remove the "aura" mechanic. id love to see lucario and mewtwo duke it out, but if I cant have both, then i'll choose mewtwo. I trust that mewtwo would have a different yet familiar moveset that most people would welcome. theres just TOO many pokemon out there! I think its inevitable that they share turns in smash bros and this is why pokemon newcomer speculation is so hard to agree upon.
Ike: I have a bad feeling that ike wont make it into ssb4, hes a great character that has a great AND unique moveset overall. he represents the fire emblem franchise very well. I think the main problem is that theres ALOT of fire emblem characters that can also represent the franchise very well. the cast of FE is HUGE. so really, its not that ike has competition against the brawl cast, its the FIRE EMBLEM cast he should be worried about. with all the new fire emblem activity, theres a good chance that we may see someone replace ike in favor of another "flavor of the month" type deal (kinda like with lucario pokemon cut speculation)
as for R.O.B. and G&W, I dont think they should be cut. a curse upon thee to those who cut wtf characters~