(I'm a Falco main with Fox, Falcon and Jiggs as secondaries, and Marth if I'm desperate)
What I've seen so far:
ZSS sorta like a mix between Sheik + Samus? Pretty ****
Falcon = Solid like usual
MK = Even being nerfed, still pretty **** (close to Jiggs?)
Zelda = With Din's mines and even more ridiculous toe tipper aerials, very ****
Jiggs = With the Brawl newcomers being converted, still decent but not as good compared to the rest (overlapping strong points with other chars)
Falco = Lots of semi-floaty newcomers, still only Fox and Falcon that he can waveshine pillar; harder to combo the Brawl chars, still decent but not as fit against the cast as in Melee
Ganon = Solid
Peach = Solid
Fox = Looks slighty slower on the eyes? Maybe LD, still decent I guess
Sheik = Seems slightly weaker, but it's still Sheik
Marth = Dunno
Ike = A Ganon aerial game with more range? Pretty ****
The rest = dunno