I know it sounds funny to be at the Hilton, but this isn't a Marriott event; it's a hotel industry conference.
If you go to some of the pages from aaupgrade's link, you'll see many hotel chains represented.
This is actually typical of an industry event; several of the participants will have press conference/announcements during the conference. I see this a lot in some of the companies that I track. Granted, the press releases are a whole lot less strange when several different airlines make announcements at the Hilton during a transportation conference than when a different hotel chain puts out a press release of making an announcement at a hotel conference being held at another company's hotel.