According to PEJ (emphasis mine),
For the week, the protests in Iran ended up being the biggest story, totaling 19% of the newshole studied during June 22-28 by the Pew Research Center’s Project for Excellence in Journalism. Though he died Thursday night, Michael Jackson’s death was nearly as big, filling 18%, and Governor Sanford’s story, which fully broke on Wednesday, was third at 11%.
But that time unit doesn’t capture the feel of the week. By week’s end, every other event struggled for attention amid the cascade of Jackson video clips and remembrances, panel discussions and interview segments…
From the time it was announced Jackson had died through the end of the day Friday—a little more than 28 hours—60% of the news coverage studied across 55 different news outlets was devoted to Jackson’s death. And that does not include the broadcast network prime time specials devoted to the singer’s demise—two of them for two hours Thursday night and one for a single—the extra hours of morning news and more.
All media sectors covered Jackson heavily, but it was cable news channels that led the way. Fully 93% of cable coverage studied on the Thursday and Friday following his death was about the King of Pop. On the front pages of Friday morning newspapers, 37% of their coverage was Jackson-related compared to 55% of the leading online coverage.