WHAT IN THE WORLD happened to Carmen Sandiego? That’s the title of a report from the Joan Ganz Cooney Center that looks at why the once-promising “edutainment era” of the nineties, ushered in by the likes of Oregon Trail and the Carmen Sandiego series, fell on its face--and what we can learn from it. The report tracks the feverish pace of mergers and acquisitions during the industry’s early history, with mass market retailers jumping in and setting off a chain reaction of downward pricing pressure and increased focus on volume distribution rather than content quality. (Remember Mattel’s acquisition of The Learning Company in 1999?)