Sonic may move up, but he's not getting out of Low Tier.I forgot to mention it earlier, but I definitely think Sonic is going to go up. He places crazy-well in tournaments. I know he's not amazing, but I never really got why he was THAT low on the tier list.
There's a large number of people who play him. Of course he'd place better in tournaments because of this.
The more people that play a character, the faster the character's metagame advances, and the better they seem to be.
Also, more people = higher chances of said character placing higher.