A tipster tells us Yahoo's upcoming layoffs could come in just a week. Among the people with their jobs on the line: CEO Jerry Yang. Sue Decker, Yahoo's scheming president, is hoping to oust him sooner rather than later, especially if pressure from Wall Street after Yahoo's surely dismal third-quarter earnings, set to be announced on the 21st, give her the excuse. Decker, formerly Yahoo's CFO, has been peddling her seat on the board of Berkshire Hathaway to convince fund managers that she has Warren Buffett's backing. If she pulls it off, it will be the third time Decker has knifed a colleague on her way to the top.Decker's first victim was Dan Rosensweig, Yahoo's COO. As CFO, Decker orchestrated a reorganization, behind Rosensweig's back, which effectively demoted him. Rather than accept this, Rosensweig quit, leaving a big hole in Yahoo's product organization which Decker has yet to fill. Yet she managed to blame the ensuing chaos on CEO Terry Semel, who soon followed Rosensweig out the door. Suddenly Yang, Yahoo's hapless founder, was CEO, with Decker as president. So will the third time be the charm? Decker never wanted to be Yahoo's CFO; she was talked into the job as a way station to a CEO job in Silicon Valley. She certainly has the political skills to land the job. But does she have the operational skills to do something with it? As an ex-CFO, Decker would be the first to admit, in private, that the numbers speak for themselves.