Titans, Hunters, and Warlocks, yes. As for the Races, nothing has been confirmed as of yet.

Each class has specific skills available that I know of. Somewhere I saw a picture of their control scheme for the warlock, L1 is a grenade, R1 in the Nova Bomb, and he can hold X (jump) to float higher/further. This implies that your guardian's 3 skills don't change. And bungie has said that race is for appearance alone. If there are racial abilities, my guess is that all racial abilities are available to all races, just at delayed rates.

heard that races will not effect anything but appearance. I can't find the link however it wasn't bungie that said it.. I also read somewhere that abilities might also be loot. As far as skills go I believe they said warlock has a skill set, hunters have a different skill set as well as titans.