The Tales of Vesperia official website has been updated with a "Special" section. The English trailer for the game is also up. The section reveals to us two things:
1) We now know the opening song for the game. It is known as Ring a Bell by BONNIE PINK. She also has her own website which contains a preview to the song, which is sort of cool. There's probably more, but this is based off of my bad Japanese translation skills, and I am unable to understand the entire post.
2) The second page isn't much, but it's still nice to see. It is a list of all opening songs with vocals in them in chronological order. It ranges from Tales of Phantasia (Super Famicom) to the unreleased Tales of Symphonia: Knight of Ratatosk/Dawn of a New World (Nintendo Wii). There is also an entry before the Tales of Phanatsia Super Famicom intro song, but I have no clue what it is.
If anyone can provide more information and have good knowledge of the Japanese language, it would be nice for you to share by commenting. (: