"According to a TV Guide interview with co-executive producer Manny Coto, "Jack starts next season in a very different place than any season so far. Let's put it this way: I wouldn't be surprised if there's no CTU next year." He also says that "There will not be a ticking clock on a nuclear device. We're hewing much closer to real life: tighter, more personal, more difficult for Jack. There may even be a plot thread that doesn't take place on U.S. soil. In a sense, it's a reboot — in location and personnel. We're going to be introducing a new stable of characters, along with a couple of old ones. Jack's not living under an alias. He's found a place he thinks he belongs and a job he enjoys doing that doesn't involve the government. What's also refreshing is the choice of villain: It's not a Muslim terrorist. In fact, it's not a terrorist at all. And the character is fascinating, someone with a supremely dark past who's done something horrific and whose ambition is to regain his stature in the world."

Director Jon Cassar and 24 executive producers Evan Katz, Manny Coto, and David Fury made some revelations at the Comic-con '07 about season 7. They stated that the show will now officially take place in D.C., and that CTU no longer exists since it was disbanded by the government. Also, they stated that at the beginning of the season Jack will be appearing before the Senate Committee to answer questions about his actions in the past, some of which they think may have been criminal. Additionally, they confirmed there would be no prequel to bridge the gap between seasons 6 and 7. They also hinted that Tony Almeida might still be alive by refusing to announce that he is dead."

Source: http://en.wikipedia.org/wiki/24_%28season_7%29#Story