We have already seen one TV spot or trailer that runs a minute long for The Host, and this is the second one. This one starts out happy, and then takes you through the plot of the film pretty quickly. William Hurt can also be heard again narrating the trailer. There have been so many, but I do believe there is a new scene in this one (the dining room scene).
Of course, this one is not embeddable, so head on over to E! Online (source) to watch it.