IANAL but my understanding is that provided the name of a public figure is used for satire or commentary the program makers are protected under the First Amendment (Free Speech) of the US Constitution.
Satire and parody are important forms of political commentary that rely on blurring the line between truth and outrageousness to attack, scorn and ridicule public figures. Although they may be offensive and intentionally injurious, these statements contain constitutionally protected ideas and opinions, provided a reasonable reader would not mistake the statements as describing actual facts.
Because liability for satire and parody hinges on a reasonable person’s belief about the truthfulness of the commentary, you would be wise to consider various factors that may help ensure that a reasonable person would recognize your material as protected ideas and opinion rather than actual facts that could be defamatory. The context of the entire publication is important, so no single factor included below is guaranteed to protect you from liability, nor is an inclusion of all of these suggestions necessary:
Still, if Cruise had objected violently, the program makers could have removed the footage from the previews that were distributed. According to reports Cruise "wasn't happy" but it seems clear that he wasn't that unhappy enough to do anything about it.
Seth Rogen @ CinemaBlend.com
"We might have got a call from his camp just kind of asking what the story was. I’m not sure how that wrapped itself up."
Rogen also admitted that he would rather not have to deal with issues regarding other celebrities.
"I’m a coward. I try to avoid those kind of things at all costs.".
Seth Rogen @ Vulture.com
Given that the show blows Tom Cruise up in the pilot, what do you all plan to say to him the next time you see him?
Seth Rogen: "I actually know Tom Cruise, so it's fucked-up. I will run into him. I'm praying he has a good sense of humor about this. I don't know how I would feel if someone exploded me, so it's hard for me to say. I hope he gets it, because I don't know if I would. But I hope he gets it, is what I'll say. You only explode people you're big fans of."