We technically knew it with DA2, but as of Dragon Age: Origins we are officially aware that the entire Qunari race… religion… thing… has essentially been retconned as well as redesigned. But they aren’t without their lampshading and they’ve done it quite well.
Bioware has created the existence of hornless Qunari, though we’ve never seen one besides Sten. Hornless Qunari are said to be more intimidating than horned Qunari and very rare. (But really, he still looks nothing like a Qunari, he doesn’t even have pointed ears.)
Interesting note? He actually looked way more like “normal” Qunari in his initial concept art, but somehow this changed.
Some other minor things have changed about the Qunari, as well–in general, they seem far less “robotic” and more personable than Sten did. So we can assume that, in general, Sten was just a particularly uptight Qunari. This could have had to do with him not having any horns; since those without horns are considered more intimidating, it would make sense that they would also have more responsibilities under the Qun.