The Hilton's standard tournament format has been discussed over at
http://www.blackjacktournaments.com/bb/
In particular, their last event featured a "mulligan" you buy for $100 to use once per round. It works like the Burger King power chip in WSOB on GSN, letting you replace one card at any time.
Other than that, it's a standard elimination format, usually with two advancing from each table.