What is this 'News Vote' thing?
The News Vote Score is built directly upon three factors:
Up to 60 points - How many prediction credits and predictions you've won
Up to 30 points - Karma you've received
Up to 10 points - Stars you've accumulated
The highest News Vote score possible is 100. So to get the highest News Vote score, you have to be perfect at the prediction game, as well as be a valuable contributing member who gets lots of karma from other members. It's not easy, but then again, it's not meant to be easy to get a high News Vote score.
Your News Vote score is also used when you submit a new front-page story. Get a high News Vote score and you've just become a newshound. A high News Vote score will immediately publish a news story. Or if enough people vote up a story, then it will get published.
Why do News Vote scores rely heavily on predictive ability? Because it's harder to game the system. And it's one (admittedly narrow) measure of intelligence.