Coors Light has officially booted Budweiser to become the No. 2 beer in America.

If Anheuser-Busch InBev (BUD) isn't panicking yet, it should be. This is the first time in nearly two decades that Anheuser-Busch hasn't controlled the top two beers in the country. The King of Beers is on its way to becoming court jester.

Budweiser has seen sales drop for years, and ran into serious trouble in 2009 and 2010. Last year wasn't as bad, but shipments still fell 4.6%, according to trade publication Beer Marketer's Insights. Coors Light shipments rose less than 1%, but that was enough to move it into second place.

The No. 1 brand is still the ubiquitous Bud Light. But since 1988, shipments of the Budweiser label have dropped by more than 60%. Ouch.

Coors Light and Budweiser are still neck and neck. Coors Light shipped 18.2 million barrels last year and Budweiser shipped 17.7 million.

"Anytime you can dethrone the king, it's special," a MillerCoors spokesman told Advertising Age. An Anheuser-Busch spokesman was less celebratory, saying the company was on track with a strategy to stabilize Budweiser.

Investors seem to be losing a little enthusiasm for beer stocks, Beer Marketer's Insights reports. Anheuser-Busch is still doing better than any other brewer, but its gains slowed to 10.5% last year from 18% in 2010. SABMiller (SBMRF) was up less than 1% last year, and Heineken (HINKF) fell 14%.

What can Budweiser do to turn its decades-long slide around? The company seems to be trying everything from dressing up its cans with bow ties to telling drinkers to "Grab some buds" in new music-heavy commercials. Anheuser-Busch even handed out free samples of Budweiser at trendy bars and restaurants.

Meanwhile, Coors Light has pushed a cool and refreshing theme, introducing cold-activated bottles and cans.

While Budweiser is slipping, craft beers are still riding a huge wave of momentum. Boston Beer Co. (SAM) shares have absolutely been on fire since October, rising more than 30%.