Well I think he's overestimating how quickly the image will change.
Take Cadillac for example... It took them a good 15 years to get Cadillac back to being cool.
I'd say they started seriously trying when the first Seville STS came out in 1988.
Though I'm sure this car will help... they have to have several years of making Buicks that fit the new image before the public image actually changes.
I think in the long run, Buick should stay as a up market near luxury brand... Plenty of space for it where it would compete against Acura, Volvo, VW, Infinity and Lexus.