From what i can tell (i just started with a bog standard human) you can play as the normal races like humans, dwarves, elves etc. but they added in 8 new races:
Sun Elf
Wood Elf
Drow
Gold Dwarf
Duergar
Svirfneblin
Tiefling
Aasimar
You get to choose your alignment, what type of head you want on your character, hair colour, eyebrow colour, skin colour, hair accessory (if applicable) colour, facial hair & colour, what deity you worship, your class, prestige classes for later levelling up, there's a crafting system in the game for making your own kit including weapons, armour, amulets etc., potions, magic stuff, a four member party, a stronghold and much better dialogue and 'story' than before.
If youve played any Bioware RPG (apart from NWN1), especially Star Wars KotOR or Obsidians Star Wars KotOR II then you'll know what to expect. Lots of compaion bantering/arguing and companion quests. There's quite a bit of player-made mods, hak packs, textures etc. out already and seeing what was created with the previous game im in no doubt there will be tons of stuff out soon, including a couple of expansion packs.
All in all, its a very good game.
Sen