????The most significant sign that General Motors is really changing came in a little-noticed announcement Wednesday.

????The automaker said it had succeeded in poaching the hottest marketing talent in the industry, a 48-year-old named Joel Ewanick, to oversee North America.

????This marks a change on several fronts. GM seldom goes after stars, preferring to promote from within, so Ewanick's arrival is a hopeful sign.

????Not only that, but GM succeeded in grabbing him after he'd been at his last employer, Nissan, for only three months. GM almost never raids other companies so brazenly.

????And to top it off, Ewanick made his reputation while working at Hyundai in southern California, a job he left only earlier this year.

????GM stealing from Hyundai! Now there is a role reversal.

????Aside from being relatively young and very smart, Ewanick is aggressive and opportunistic. He runs his marketing operation like a campaign war room, looking for opportunities 24-7 and then seizing them.

????Ewanick has worked with some impressive brands. He held marketing jobs at Porsche, Yamaha, and Hinckley Yachts before joining Hyundai in February 2007.

????He's best known for leading the creation of Hyundai's famous assurance campaign a year and a half ago, in which the company promised to buy back a car from anybody who lost his job.

????Ewanick launched the campaign, which included a Super Bowl commercial, during the height of the financial crisis -- and did it in just 37 days. And even though only about 100 customers returned their cars, the campaign won Hyundai enormous amounts of attention and goodwill.

????As Ewanick told Fortune last year, promotions like that are vital because buyers have gotten used to traditional cash and interest-rate promotions. "Customers want to be involved with the brand," he said. "Incentives aren't enough. We want to break away and have Hyundai be considered as more than a car company."

????Don't expect to see any attention-grabbing stunts like that at GM. The company has more than enough visibility. What it needs to do is to convince buyers that its familiar brands -- Chevrolet, GMC, Buick, and Cadillac -- are still relevant.

????Blogger Peter DeLorenzo, a frequent critic of GM marketing, outlined the most visible part challenge in his latest Autoextremist rant: to create advertising "that captures that elusive mix of spot-on strategy and flawless execution [that] becomes the buzz of the moment [and] leaves a favorable impression for a product that endures."

????But advertising is only part of the job. Ewanick really needs to freshen GM's appeal at time when competition is tougher than ever.

????On the downside, Ewanick's arrival means more upheaval for North America's marketing organization, which has undergone several reorganizations in the past four months. There will doubtless be more personnel changes, more outsiders arriving, and more ad agency reviews.

????His appointment also reinforces the view that North American boss Mark Reuss, and his boss, CEO Ed Whitacre, are flying by the seats of their pants and experimenting to see what works.

????One prominent dealer described the situation at GM a few weeks ago as "chaos," and this latest change will do nothing to disabuse that view.

????But if Ewanick's hiring signals a change in thinking about new ideas, not to mentioned smarter marketing of GM brands, it is all to the good.