I don't get the soap opera effect necessarily, but motion blur goes a long way to hide the CGI nature of graphics.
It forces your eyes and brain to interpolate and add details that just aren't there.
Why this happens is also clear when using photo mode; when you want to trick people into thinking they're looking at a real picture, or take a good looking picture anyway, you need to hide the occasional lack of detail in the distance, either with DOF or MB, or both.
Clean 60fps look great, it also looks more clinical as in you can often make out single polys and individual pixels, which I'm usually not a fan of, depending on the aesthetics the game is going for.
Granted, 10 minutes at 60fps and it will be impossible to go back, regardless of what look you prefer.
Also, dying to see this in HDR. Which I won't anytime soon; malls here are so behind when it comes to demoing new stuff.