Each week Ross Rubin contributes Switched On, a column about consumer technology.
Throughout the history of home game consoles, it's been notoriously difficult for a leader in one generation to maintain its leadership in the next generation. Sony, for example, went from dominance of the sixth-generation console market, knocking Sega out of the hardware business as Microsoft was gearing up for the original Xbox, to a third-place finish in terms of installed base with its seventh-generation entry, the PlayStation 3. Last November, Switched On discussed how Nintendo turned its back on muc