It seems to be going to vodka distillers. Have you seen the number of high-end vodkas now on the market? They make Absolut look cheap by comparison. I priced a 750ml bottle of Ketel One at $23 yesterday.
I think a possible reason for the decline in beer sales is due to crackdowns on beer sales on college campuses.
I visiting my old college campus a couple of years back and one of the first things you notice is that jack & coke replaced beer as the drink of choice.
In many areas authorities have cracked down on beer drinking by forcing kegs to be registered and forcing those who buy kegs to sign liabilit statements stating that minors won't drink, and that the place where the keg is located must be open to police inspection.
As a result, college parties now more than ever feature mixed drinks instead of beer.
Someone should tell those buyers that Jack Daniels has recently been diluted (they claimed that customers WANTED less alcohol content!).