From what I can gather, Dragon Age looks like BioWare's follow up to NeverWinter Nights without the AD&D settings, D20 system, etc. It seems BioWare want's to move away from developing games based on someone else's property and start developing their own. Thus Dragon Age and Jade Empire.
I expect Dragon Age to be much like NWN. Single and Multiplayer system, heavy online play with improved tools for creating your own adventures. More DM interaction, and improved graphics engine to handle more actions in a 3D environment. (Swimming, flying, etc.)
I guess E3 will mark it's first real public showing as info will begin to trickle out from there.