How smart will the grid need to be for plug-ins?

Is the grid ready for plug-ins?

The Department of Energy is awarding $620 million for smart grid demonstration projects. And that's fine. Of course, inevitably, one must ask how much will full scale implementation cost?

Numerous estimates thus far have put the cost at hundreds of billions. Yet, even some utilities have claimed that very little smart grid technology - if any - is necessary to get plug-ins going. Of course, that's a very regional issue.

Nonetheless, what is the future of the plug-in vehicle?

Many studies, for instance, have suggested that the most efficient plug-in vehicles are either short range plug-ins hybrids, or pure EVs with swappable batteries. If market forces eventually dictate this reality, how much of a smart grid is really needed to electrify America's transportation system?

Ultimately, is the plug-in revolution - a majority of market share - totally dependent upon hundreds of billions of smart grid technology? Or are plug-ins only one variable in the need for a new grid? Also, is there any danger this might lead to an over-centralized and monopolized energy infrastructure?