Weekly World News, the tabloid that for 28 years has chronicled sightings of Elvis, extraterrestrial activity and the exploits of Bat Boy, is no more. Its publisher said Tuesday it would put out its last issue next month, maintaining only a Web presence.What does it mean for a black-and-white staple that has delivered news of such historical proportions as Bigfoot's capture of a lumberjack he kept as his love slave and the merman found in the South Pacific? Stay tuned. One thing's for sure: Americans' waits in supermarket checkouts will forever be changed.