Cody's theme in SSFIV is heavily based off of the intro from Final Fight. The rapper repeats the words "Turn the beat back!" quite often. This is a look into Cody'spsyche; he longs to relive his glory days as a hero and get out of his funk, but sadly has convinced himself that things can never go back to how they were.
Near the end, the song gets rather uplifting and whimsical...until it loops and goes back to being a gritty rap. More than likely, it's Cody remembering his time as a hero, only to go back to his current, uncaring self.
One aspect of the US marketing was slapping on surnames to some characters, and Ryu became Ryu Hoshi. Factor in the Japanese name order, and it ought to be Hoshi Ryu. And 'hoshi' means 'star' so the full name in kanji can also be read as Seiryu - one of The Four Gods.
Dan is significantly less wimpy in Streetfighter IV than in previous appearances. You might think this is because the developers are just trying to make him more fun to play but think about what Dan has been doing for the past three years. He's been hanging around with Blanka and Sakura. Even if he is getting his butt kicked regularly, practice with both fighters is bound to improve his fighting style.
Juri hates Shadaloo for killing her parents and maiming her. S.I.N. is stated to have been Shadaloo's weapons division. In her Story Mode, Juri joins S.I.N. and works for its leader, Seth. Is it that she has/had no clue of the link between Shadaloo and S.I.N.? Well, if you examine her ending, it can very easily be a case of her playing the role of The Chessmaster, playing both sides against each other to make the whole organization destroy itself from within—that would be her ultimate revenge!