[magnum12]

Sonic: Roger Craig Smith
Tails: Kate Higgins. Sounds fantasttic
Knuckles: Travis Willingham.
Cream: Michelle Ruff. Major improvement. Reminds me of a much younger Tsukasa (Lucky Star).
Shadow: Kirk Thornton. Based on what I heard, he's going for a darkly charasmatic approach with Shadow.
Omochao: Laura Bailey. Major improvement. Imagine a mechanical Raspberyl (Disgaea 3) or Rise (Persona 4) and you have this voice in a nut shell.
Storm: Travis Willingham. Sounds like Recomme.
Rouge: Karen Strassman. Major improvement over previous ones.
Amy: Cindy Robinson. Too much like Minnie Mouse. Okay, but would be better if the pitch was a bit lower.
Wave: Kate Higgins.
Jet: Michael Yurchak (credited as Mike Mycheck)
Big: Kyle Herbert.
Vector: Wally Wingert
Silver: Keith Silverstein
Blaze: Laura Bailey. Although I was expecting Blaze to sound like Konan given her reserved personality, I like this voice. It still manages to get a regal feeling (young royalty) and shows the progression Blaze got later in the Rush series (more open, etc).
Espio: Troy Baker. What it sounds like is unknown.
Charmy: Collen O'Shaugnessey. See Espio.
Omega: Vic Mignonnia.

[EngiNerd]

Knuckles sounds almost EXACTLY like he did before.  Also, I kinda dislike Shadow's new voice but I sense it'll grow on me when I actually see him using it.  Cream and Omochao are DEFINITE improvements, it gives me hope that Charmy is actually not-annoying this time.

[Shadow Jacky]

I kinda want to get this game just for the new voices

[Parax]

I'm actually impressed with Shadow's and Rouge's new voices... but wow Amy and Cream sound like total crap. :/

and since no one linked anything in here yet <_< I found this on youtube: http://www.youtube.com/watch?v=iNiaDRSSJ6Y

[magnum12]

I find that Knuckles sounds like a more firey, hot blooded Dan Green. I didn't have any real problem with Dan Green's Knuckles barring the lack of being hot-blooded, so that's not a bad thing IMO. I like the new Shadow, though I admit that its going to take a while to get used to him. Sort of like the situation I had with Mao in Disgaea 3 when going from the Japanese version to the US version. Disagree about Cream though. As I said earlier, the problem with Amy is the pitch (though I would have personally cast Laura Bailey or Stephanie Sheh as Amy). If that gets lowered, then she sounds much better. As a whole, its a solid cast. Special props to Kate Higgins for being the first truly great Tails. Egg Man being awesome is a no brainer.

[IsisDazs]

Interesting new blend - I don't mind the new voices. Shadow's is an improvement from Griffith, and Rouge doesn't have Old Hag Syndrome™ anymore. Omochao reminds me of Ed from Cowboy Bebop.

[Luxray]

I am happy that Mike Pollock is still Eggman's voice. Every since 4Kids, that has probably been the only tolerable and acceptable voice. And listening to the new Colours trailer, i can say that Tails and Sonic sound much older :/

[SonicandInuyasha]

I like the only Sonic fan that likes the 4kids voice actors. I like Jason as Sonic. He did his very best in Sonic Unleashed and Sonic and the Black Knight.

[ieatatsonic]

Here's my opinions (in order of the video Paraxade's linked video)
Omochao- VERY nice.
Tails- Better. No more high-pitched.
Sonic- Pretty bad. I don't like him as much as the previous one.
Knuckles- Sounds pretty good.
Amy- sounds like Cream did. Sucks.
Vector- sounds the same, so it's good.
Cream- Yes, it sounds too much like Tsukasa, except clearer. I honestly think it's one of the best.
Shadpw- Idunno.
Rouge- It's just.... out of character to me.
Wave- very nice. Fits her personality, if any.
Jet- I liked the old voice. This one seems like it belongs in a looney toons cartoon.
Storm- Big. Silver- Same, or at least it sounds that way. Blaze- Very good & fitting.

[DBG]

I like the only Sonic fan that likes the 4kids voice actors. I like Jason as Sonic. He did his very best in Sonic Unleashed and Sonic and the Black Knight.

Not the only one. But I'm not very critical about voices; it just takes some getting used to whenever the voice actors are changed around.

[Cutiefox]

Knuckles: Travis Willingham.

This is exactly what I wanted.

[SonicandInuyasha]

One of my youtube friends is going to hate Omega's voice. He hates Vic Mignonnia. I watch a little bit of FMA. I don't bother watching the whole anime since I love Inuyasha way more.