Over on Sega Europe's blog, the latest European release dates for Sonic Unleashed have been posted. There has been much speculation over these, as every retail website gives a different date.
Anyway, Sega have confirmed that most versions of the game will be released on November 28th, whilst the PS3 version has been delayed to December. There is no definite date for this. Release dates for North America have yet to be confirmed.
I'll update when there has been more release date confirmation.