Nicole Greenfield: Al Jazeera English made its on-air debut today with high hopes of becoming “the first non-Western source to challenge the global info-supremacy of CNN and the BBC.” But don’t expect to see it show up on your channel listings — not one U.S. cable company was willing to pick it up. And don’t expect to see much press about it either. The Washington Post seems to be the the only paper giving the story the attention it deserves.