I didn't like the Golden Hammer. In theory it was cool, but why make a dud version of an already rare weapon? I always got the squeeky version. At least make it distinguishable like the Poison Mushroom. As for the other items...
Crates and barrels are cool, especially with them being able to be different designs for different stages. Rolling boxes, while fun, are a little too hectic at times, maybe. Maybe make them rarer.
I like the capsule redesign.
Party ball should go. It feels too kitschy for me.
Sandbag Bob (as I've called him since I was a kid) needs to stay and be abused.
Banana Peel should be a Diddy-exclusive item
Blast Box should go. Enough explosive stuff as it is, looks too close to the crate.
Bob-Omb is a classic, as are the shells. Bring back the Red/Green, but maybe Blue also? Hits the guy in first?
Bumper is a classic. I love it.
Bunny Hood needs jiggle physics.
Beam Sword is alright, it's a classic, and can't wait to see it's new design.
Blaster's new look is a lot cooler.
I want the Homerun Bat back, but make it Earthbound based maybe. In Brawl it said it was a "generic item". Why not just slap a sticker of an Earthbound thing on it?
I wonder if the Super Scope is coming back. I loved that for an item, it was Nintendo-based but also cool.
Cracker Launcher felt unnecessary, and hard to use. Wouldn't mind seeing it gone.
I want Urina replace with a Gordo.
Deku Nut, I never liked. It's too small and too easy to hit yourself with.
Dragoon, see previous posts. Don't like.
Fan, while a classic item, I would like to see go. It's a little too Japanese in a really multi-cultural game, the joke of it is lost on everyone not in Japan.
Fire Flower is cool.
Food, I still want it 2D. I think it's hilarious.
Franklin Badge was awesome, but it would be nice if it had some other visual effect, like an aura or something. Same for the Screw Attack.
Freezie is fine, though I might prefer it like the Banana Peel an Ice Climbers exclusive item, mainly for their Neutral B.
Gooey Bomb should go. Mega Man's Crash Bomber is literally it.
Heart Container and Maxim Tomato have to stay, Team Healer, no. I've never found actual use for it.
Hothead, no.
Lightning Bolt was cool, but can it work like in Mario Kart? The person in last gets un-shrunk sooner than the person in first?
Metal Box is gdlk
Motion Sensing Bomb stays, but needs a redesign.
Mr. Saturn, if any of you fucking says he has to go I swear to god I will rip you a new one.
Pitfall was great.
Mushroom/Poison Mushroom, yes. I like how it's just barely noticable, just gotta look at the eyes.
Smart Bomb, I like, but no or a lot fewer duds please.
And Smash Balls, Poke Balls and Assist Trophies are already confirmed and totally awesome.
*whew*
That's a lotta items.