From playing the game, watching the game, and discussing this with the other knowledgeable smashers there, this is what it's looking like:
Mario, Meta Knight, Peach all share the ability to combo fairly easily.
Meta Knight has a "disjointed" feel to his attacks, as well as some attacks that deal out significant damage fairly easily by themselves (specifically Smash+B).
Meta Knight and Peach have great recovery. Mario seems to be able to chaingrab with D-throw on some characters (Ike? Sonic?)
Bowser looks slightly improved in general though some of his better moves might have been downgraded a tiny bit (Fortress); he's heavy, and strong.
Fox is not anywhere as fast or broken as he once was (specifically his U-throw to U-air is nerfed as well as pretty much anything else you could say was once broken) - he is however still pretty fast relatively speaking.
Diddy has speed and can get combos going but seems to be on the weaker side.
Link looks more agile, had his Spin Attack nerfed (doesn't spike, smaller, weaker, but can be charged).
Pit has some nice attacks, broken recovery, possibly Top Tier once we get more info on him.
Pikachu looks very much like his Melee version with some of his moves slightly bumped (Thunder and others) and other moves slightly nerfed (U-air doesn't "spike" and U-smash is weaker).
Samus seems to have had all her perks slightly nerfed, especialy missiles, charge beam, and bomb jumping.
Sonic's dash is the best in the game and he seems to be good at comboing. He seems to lack speed when attacking thus far, might be easier to combo than average, and might be weak in general (need more info).
Zero Suit samus has got good combo potential, but I haven't heard nor seen much of her. She appears to be far from a remake of Sheik though.
DK is rather sluggish and large. I'm going to need more info on him, but without L-canceling it seems he has a bit of a problem with comboing.
Ike is easily the slowest character ever seen... like Giga Bowser slow! He's also easily the strongest, like Marth with auto-tippers when he hits. We need to find out about his no-flinch frames which could easily boost his status.
Yoshi looks like his Melee counter part, but he's got some nice updates, specifically his Up+B and Smash+B as well as his increased range in his attacks (B-air is very noticeably improved).
I really need input from the rest of you guys that attended E for All - also, we will have more info after each of the days. Gimpy's the official voice for Bowser as far as I'm concerned, as is Hugs for Samus, Gabe for Yoshi, and Trevyn with Link. I'd also like to hear some feed back from Festizzio and t0mmy about Pika, Mike Haze and Eternal Phoenix Fire for Fox, and Neal for Peach since I saw them playing those characters a lot.
We're sure to learn loads more once Nor Cal gets their hands on Brawl today!
EDIT/NOTE:
The above Tier List has a pretty small margin between it! It's not like Melee's list at all in terms of power and capability. If it was like Melee's, it would be more like "Middle Tier" split into three parts with the possibility of Ike being a true Low Tier at this point.
Edit: tier list updated to relate to Melee's power level.
Upper Middle
Mario, Meta Knight, Peach.
Mid Middle
Bowser, Diddy, Fox, Link, Pikachu, Pit, Samus, Sonic, Zero Suit Samus
Lower Middle
DK, Ike, and Yoshi appear to be on the lower rung.
Reasons:Mario, Meta Knight, Peach.
Mid Middle
Bowser, Diddy, Fox, Link, Pikachu, Pit, Samus, Sonic, Zero Suit Samus
Lower Middle
DK, Ike, and Yoshi appear to be on the lower rung.
Mario, Meta Knight, Peach all share the ability to combo fairly easily.
Meta Knight has a "disjointed" feel to his attacks, as well as some attacks that deal out significant damage fairly easily by themselves (specifically Smash+B).
Meta Knight and Peach have great recovery. Mario seems to be able to chaingrab with D-throw on some characters (Ike? Sonic?)
Bowser looks slightly improved in general though some of his better moves might have been downgraded a tiny bit (Fortress); he's heavy, and strong.
Fox is not anywhere as fast or broken as he once was (specifically his U-throw to U-air is nerfed as well as pretty much anything else you could say was once broken) - he is however still pretty fast relatively speaking.
Diddy has speed and can get combos going but seems to be on the weaker side.
Link looks more agile, had his Spin Attack nerfed (doesn't spike, smaller, weaker, but can be charged).
Pit has some nice attacks, broken recovery, possibly Top Tier once we get more info on him.
Pikachu looks very much like his Melee version with some of his moves slightly bumped (Thunder and others) and other moves slightly nerfed (U-air doesn't "spike" and U-smash is weaker).
Samus seems to have had all her perks slightly nerfed, especialy missiles, charge beam, and bomb jumping.
Sonic's dash is the best in the game and he seems to be good at comboing. He seems to lack speed when attacking thus far, might be easier to combo than average, and might be weak in general (need more info).
Zero Suit samus has got good combo potential, but I haven't heard nor seen much of her. She appears to be far from a remake of Sheik though.
DK is rather sluggish and large. I'm going to need more info on him, but without L-canceling it seems he has a bit of a problem with comboing.
Ike is easily the slowest character ever seen... like Giga Bowser slow! He's also easily the strongest, like Marth with auto-tippers when he hits. We need to find out about his no-flinch frames which could easily boost his status.
Yoshi looks like his Melee counter part, but he's got some nice updates, specifically his Up+B and Smash+B as well as his increased range in his attacks (B-air is very noticeably improved).
I really need input from the rest of you guys that attended E for All - also, we will have more info after each of the days. Gimpy's the official voice for Bowser as far as I'm concerned, as is Hugs for Samus, Gabe for Yoshi, and Trevyn with Link. I'd also like to hear some feed back from Festizzio and t0mmy about Pika, Mike Haze and Eternal Phoenix Fire for Fox, and Neal for Peach since I saw them playing those characters a lot.
We're sure to learn loads more once Nor Cal gets their hands on Brawl today!
EDIT/NOTE:
The above Tier List has a pretty small margin between it! It's not like Melee's list at all in terms of power and capability. If it was like Melee's, it would be more like "Middle Tier" split into three parts with the possibility of Ike being a true Low Tier at this point.
Edit: tier list updated to relate to Melee's power level.