General Motors (NYSE:GM) product development chief Mary Barra told reporters on Wednesday that GM's future green-car efforts would focus on plug-in hybrids and pure electric vehicles, rather than conventional hybrids.

Rather than going head-to-head with companies like Toyota (NYSE:TM) and Ford (NYSE:F) that have made big investments in hybrid powertrains, GM has narrowed its future product development emphasis in an effort to defend and expand on the technological lead it established with the Chevy Volt, Barra said.

It's an interesting shift in strategy. But the really interesting part is that Barra expects these cars to become a big part of GM's business – soon.

"Mild hybrids" to roll out in big numbers
Barra said that by 2017, the General expects to be selling 500,000 vehicles a year with some sort of electric propulsion technology, whether plug-in hybrids, pure EVs, or "mild hybrids."

That number sounds outrageous, but it represents only about 6% of the roughly 9-million vehicles GM sold around the world last year. And it's easy to take a conservative view and say that most of those will fall into the "mild hybrid" category: GM's "eAssist" system, already available in some Buick and Chevy sedans, is a sort of battery-powered mileage booster.

Those cars can't run on pure electric power, like a Prius or Fusion Hybrid can, but they do get significantly better mileage thanks to an electric-powered assist – up to 25% better, in some cases. Cars with eAssist account for about half of the roughly 50,000 vehicles GM has sold in the U.S. this year that contain some sort of electrified propulsion technology.

An evolution of the eAssist system might account for the bulk of GM's target of 500,000 sales in 2017. But it's not where GM's research dollars are likely to be going.

More advanced cars on the way
Barra said in a statement released by GM: "Plug-based solutions will play a significant role in our technology portfolio going forward ... The plug-in offers a unique opportunity to change the way people commute."

Barra is talking about both pure electric cars and so-called "plug-in" hybrids, which can be charged via external sources and give a limited range – typically 20 or 30 miles – without using any gas. The Chevy Volt is perhaps the most famous, but Toyota, Ford, and others have introduced plug-ins of their own, or announced plans to do so in the near future.

GM's near-term plans include an all-electric version of its Chevy Spark minicar, which is set to go on sale in the U.S. and Korea next year. The Spark EV was originally thought to be a token gesture by GM, one intended to help it comply with new U.S. fuel-economy rules – but Barra insists that GM is serious about selling it. "We're not building the Spark EV to check a regulatory box," she said.

As for the Volt, sales have been middling, in part because of its high price. But it's about to get an upscale sibling: The Cadillac ELR, a swooping and luxurious two-door that incorporates the Volt's technology, will also enter production at GM's Volt factory in Detroit next year.

The upshot: GM is getting serious
It's easy to see all of this as posturing by the General. While Toyota and Ford push far ahead with more advanced hybrids, and Motor Trend's "Car of the Year" award went to Tesla Motors' (NASDAQ:TSLA) stunning Model S, GM needs to say something to show that it's still in the game, now that the Volt is old news.

But I think GM is serious here. Part of the seriousness comes from knowing that electric car efforts will continue to be encouraged by the U.S. government, now that President Obama has been reelected.

More to the point, I think GM's current management team – in contrast to some of its predecessors -- knows that the General will need more than gestures to be taken seriously around the world as a green contender in coming years, no matter the political environment here in the U.S.

With the auto-show season about to begin, I won't be surprised if GM announces some significant new products that take advantage of advanced electrification technologies. In fact, I'll be surprised if they don't. Stay tuned.

Fool contributor John Rosevear owns shares of Ford and General Motors. You can follow his auto-related musings on Twitter at @jrosevear. The Motley Fool owns shares of Ford and Tesla Motors. Motley Fool newsletter services recommend Ford, General Motors, and Tesla Motors . Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.