It's official: General Motors is off the Dow, and Cisco takes its place. The transition is more than just a dry Wall Street accounting maneuver: From a cultural, economic, and societal perspective, it marks a seismic shift in how our world is organized.

For starters, it embodies the transition from the transportation age to the communications age. We're now in what might be credibly called the "post-automotive" era.

Many predict that the American love affair with auto ownership has run its course, for a whole host of reasons: rising oil prices, an increased preference for denser, urban environments, lack of resources (especially among the Gen-Yers coming of age in a financial crisis), and an overall cultural shift towards long-term sustainability. Even companies such as Hertz have gotten into the act. The company now offers hourly rates and "car-sharing," with the goal of making it possible for people to procure cars on a "just-in-time" basis — thereby avoiding having to own cars at all.

At the same time, communications technology is ubiquitous, and continues to rise. Cell phone deployment in parts of Europe recently exceeded the ratio of 1:1 (more than one mobile device for every man, woman, and child). In fact, just as many households are questioning the necessity for owning a car, they're stocking up on routers. A significant percentage of US households now own routers, and the number continues to climb.

These days, there's also the cultural expectation that distance doesn't matter. Parents regularly videoconference with their kids. Former schoolmates keep in touch with Twitter and Facebook. And telepresence is beginning to take off. In other words, virtual presence is increasingly replacing the real sort.

So the GM/Cisco transition definitely marks the end of an age dominated by the idea of moving people, and formally inaugurates the age of moving bits instead.

There are other cultural and economic implications of the shift: General Motors' manufacturing plants are a storied part of American history, while Cisco's products are designed in the United States but largely assembled elsewhere — not good news for the next generation of American line workers. General Motors is headquartered in the Midwest, while Cisco's on the Left Coast. GM workers are often high school educated and unionized; Cisco's are typically college-educated, nonunion. And so on.