Ah, I'm glad you asked. Unfortunately, the G. Heileman Brewing Company is no longer (former brewer of Old Style, which is now brewed by Pabst - it's a mad, mad, mad world). However, the facility was purchased by City Brewing Company, which is using most of the facility brewing dozens of beers, teas, malt beverages, energy drinks, etc. Think Mike's Hard Lemonade, Arizona Tea, etc. City Brewing Company purchased the old Rolling Rock facility in Latrobe, PA, and I think is brewing Sam Adams and other such beers there. So, City Brewing Co is a contract brewer, and doesn't own the trademarks or intellectual property of the beverages it makes.
http://www.citybrewery.com/default.aspx
The World's Largest Six Pack still exists, but even THAT has been rebranded:
http://www.roadsideamerica.com/news/8137
Madness!