Fusion-io uses densely-packed clusters of flash memory chips in servers to enable them to find data very quickly. Woz has been serving on the board at Fusion-io, and recently asked for a larger role. "In this case, I like the people and the product, and said I would like some greater involvement," he told The New York Times. This will be Steve's first full-time job since he shut down Wheels of Zeus in 2006.
Good luck, Steve! We're looking forward to seeing what's next.