Budweiser took a beating but they were not the only one's. Miller Lite and Coors Lite also declined in total shares. The only difference is that Budweiser switched to the number three spot as the industry takes a downturn. There may be some market trends going on here.
-While these industries think of their beer as premium they are now seen as somewhat generic compared to craft beer. Americans are changing their tastes and moving to wine and craft beer. The new generation will likely keep this trend going.
-There is a movement toward the boutique. This is something large businesses might have some difficulty overcoming.
-Trends toward healthy and organic. To be honest these mainstream beers are low in calories and probably healthier for you than many craft beers. They may be able to tout this to their benefit.
-Old Brands. These brands are getting old and loosing their flair. They have lost their specialty flavor that was once associated with European traditions, draft horses, and a simpler life.
-Flavor can be improved. While I find the plain flavor appealing many want something more fruity or citrus oriented like craft beer. They may want to consider blood orange, coastal, and other flavors found in craft brew parlors.