After seeing this post
http://www.livejournal.com/community/dragoncon/544830.html, I talked to Gloria at the front desk of the Hyatt about the sign just now. She says she's worked there for 9 years and though bringing in Alcohol is against the state, city, and county liquor license, food and non-alcoholic beverages are fine to bring into the hotel.
To make it even more official, I've spent the last 3 hours searching for any kind of information online, through city, county, and state websites that would back up the food and non-alcoholic beverages ban, but there is nothing to be found.
What I was able to find was that the Hyatt decided to institute its own rules on bringing in food and beverages (though there was no definition to alcoholic and non-alcoholic). I found this same document through a few sites but this seems to be the more official one
http://www.inta.org/annual/2004/pdf/exh_guidelines.pdf.
From what I can gather, the "corking fee" is basically you giving the alcohol to the hotel, and them selling it back to you, doing this means they have sold you the alcohol and it is allowed to be stored and consumed on the property.
Just some information to try to help straighten everything out.