worse than Melee? I really doubt that, It'll be better than Brawl, Melee, 64 and even Project M. Smash4 wil be the Smash that will define all Smashes to come and outdate ones prior, a true celebration of Nintendo history with simple, but deep gameplay mechanics that make it an absolute delight to play and watch, the Blue Bomber, the Blue Blur and the Legendary Plumber all together, Villager finally playable, and if Ridley turns out to be playable, then that'll be even better.
So no, it won't be worse than Melee, it's already better than Melee and we haven't even played it, with the fast-rolls, I predict exciting, unpredictable competitive matches.