Eidos Montreal just released a new trailer for Deus Ex: Human Revolution, and you hear quite a bit of Adam talking in this one. Adam’s an ex-cop, so you get to see a bit of his detective side, too.
Adam isn’t straight as an arrow though. He can also do some pretty shady things if you want him to. The ESRB gave away a few hints about this aspect of the game in their rating summary for Human Revolution.