As current Avaya CEO Lou D'Ambrosio steps down due to health related reasons, Charles Giancarlo will move from his role at Avaya's owner, private equity firm Silver Lake, to interim CEO. Industry watchers long expected Giancarlo to take the CEO's office — just not at Avaya. Word has it Cisco's John Chambers wanted Giancarlo to be his successor. When Giancarlo left Cisco in December 2007, Chambers told reporters: “Charlie’s been one of the very few leaders that I’ve lost out of Cisco when it wasn’t the right time to lose him."

Once upon a time, Charlie Giancarlo was Cisco's crown prince, the heir certain to CEO John Chambers. As chief development officer, he oversaw a vast swathe of future products. But his power was recently cut back, with R&D responsibilities handed over to a council of executives. Now Giancarlo has resigned, and he's joining Silver Lake Partners, the tech-buyout fund. Not for long, though, we'd bet. Private-equity funds like Silver Lake and Elevation Partners are proving convenient places to park CEOs-in-waiting. Think of Giancarlo's career move as a temporary exile as he searches for a new kingdom.