This week it's HURRICANE WEEK: EXTREME IMPACT. The programming schedule is pretty much the same thing as the "Without Mercy" week back in June. The 8 PM hour of WC and the 2 AM hour of WC will be replaced with long form.
Also. According to my guide, there's an old special going to air at 8:30 ET; called "In His Own Words: Brian Williams on Hurricane Katrina". NBC's Brian Williams tells his side of the story on Hurricane Katrina. It says it's first aired in 2005 so I'm assuming it's not new.