i will now attemp to give descriptoions based on what i know spoilers=.:
marth- still owns the game apparenty,possibly better than he was in melee
diddy - fast,best combos, projectiles, hes really good
wolf- strong,fast, better reflector pit - has it all,rocovery,projectiles,unique attacks,range, only flaws is lacking k.o. moves(i ve heard him called marth with wings)
falco- plays alot different but still good,throws reflector,shl not as effective, new A moves
zsamus-like shiek with a gun and whip, effective combos
lucas- imagine if ness was good in meele thats lucas, he has good mingames with his b-m0ves can short hop pk fire, heard someone say hes has potential to be the best character in the game
fox-plays alot different, shine is still effective, good speed, areals still needs time too devop too see exactly how he plays
shiek-virtualy unchanged from melee, weaker fair, less range on needles
samus-basicly played the same with mindgames except no missle cancel
metaknight- good, but not as good as he looks, preety much everyone has seen metaknight in action
squirtle-fast comboer said to be the best of the 3 pokemon
ike-strong, not as slow as he was made out to be, definetly a useable character
olimar- can rack up damage with pikmin, purple pikmin are strong,bad recovery
dedede- hes like bowser with a hammer, waddle dees are good projectile, good throw and r3covery
peach-nerfed down smash, n0 float cancel, said to be averaged out
g&w- improved alot from melee, upb parachute floats,attack out of up b
lucario- like mewtwo with better areals and speed, floaty, hard to play, but has potential
mario-good solid character, average,same as meele,fludd is useless
ivysaur-average,good range and attacks
sonic-fast,hard to play,not much varietty in bmoves, good smashesfalcon- slower,weaker knee,still good comboer,bad recovery
luigi- same as meele, no wd
jiggly-same as melee
toon link - fast , good projectiles rob - not that bad, some people say hes awsome, he has lazers and recovery
link-same as in meele,boomerang sucks people in, probly more usable than he was in meele
ganon-cant l-cancel, can techchase with his side b which is new, slow,strong
charizard-strong, good recovery,and good ko moves
ice climers-no wd,can still desyncsnake- plays alot different than other characters, takes alot of skill to use, slow
everyone else same as meele with minor changes
yoshi-fast but sucks, no djc or jump out of shield,