I'm not a big fan of making something different just for the sake of being different. If I were to look at a world with classes named Domani and Spykers and what-not and strange races... it would seem to me like the designer was maybe trying a little too hard.

Some things work well for a very good reason. Most people expect certain things from fantasy, and we are not out to alienate them... nor are we approaching this from the idea of "everything D&D does is wrong and we want to stay away from that". While at the same time, we want to put our own spin on many of these fantasy elements and even introduce some concepts of our own. With a whole world to explain along with an entire game system, however, it's also an effort to make sure you don't overwhelm the player.

So will you see some of the standard roles in the DA classes? Yes, you will. You will also see some very different stuff. I'm sure some of it will not be different enough for some folk, but I suppose that that's inevitable.