That'd be creepy indeed. Clint Eastwood looking at you. He'd be all "So, punk, why you eating Dorito's? eH punk? MSFT wants you to eat Oreo's!" in that weird voice of his.
Nope, not gonna have Eastwood as my Cortana. No way. It's weird to see a digital old man look at you and tell you can't your favorite snack.