From http://www.continental.com/travel/tc...Operations.asp
Due to approaching Hurricane Rita there is a mandatory evacuation in many areas along the Texas Coast. Departures out of Houston will cease at 1230P/CDT Friday, September 23 due to Hurricane Rita. Currently, all operations out of Houston scheduled for Saturday, September 24, have been cancelled. Resumption of service is tentatively planned for Sunday morning, September 25, pending further review of the weather situation.

Carol called about 4pm EST and said that their flight is still on the schedule. The FAA site says that flights out of Houston are delayed on the runway for 30-44 minutes.