Shadow

From the look of it I think they've just made her dress have less of a bell shape at the bottom. I can't imagine them doing away with it altogether. At least I hope they haven't. And Knuckles definitely looks the strangest, it's like he's grown a few feet taller, and his arms aren't the traditional 'pipe cleaner' type anymore. He almost reminds me of a werehog.

Wait ... like some kind of muscled knuckles ?

brrr....

Well, it could be possible that they are giving the characters a small redesign to appeal more to the young public. Considering Amy, since you don't even have to take effort to look under her skirt and you know, kids... And then they gain access to the internet... You know where I'm going with this.