Due to shrinking viewer audiences, the USGA has stated that they've made a conscious effort to try and add a little excitement to the U.S. Open.
Watching the best players in the world, constantly hack it out sideways back to the fairway, from 6 inch rough, because of being 5 yards offline with their drives...is really boring.
The low scores on the first day, were due primarily to absolutely perfect scoring conditions (lack of wind/moist greens)...and I doubt will be reflective of the final winning score.
If the winning score is around 15 under...I'm personally fine with that.