Sara and Tom are characters. Are you meaning the actors who were cast to play them are still attached?
Found some casting notices. The first is the original notice and the second one is the lastest notice. You can see how much the project has changed.

The name has even changed a few times.
First posted Jan 2007(Los Angeles, CA) -Title:
NSA INNOCENT, TV Pilot for FOX. EXEC PROD, Joel Surnow, Bob Cochran, Howard Gordon, David Ehrman; DIR, Jon Cassar; WRTR, Bob Cochran, David Ehrman. Contract: SAG. Shoot Dates: March, 2007 (in Los Angeles). Breakdown-- Paul Fisher: Late 30's-Early 40's. He's the NSA innocent. Athletic, but also intellectual, he is a scientist at home in the world of ideas and abstractions. Married with a sixteen year old son, his family life is undergoing some strains, which are greatly increased when the NSA forces him to spy for them, in absolute secrecy (even from his wife) on a co-worker suspected of treason. In the course of the pilot, and the series, Paul will discover inner resources and strength which allow him to survive in this unfamiliar and brutal world. Name Actos. Series Lead; Kate: Late 30's. Paul's wife, a surgical nurse. Pretty, independent, caring, and in love with her husband but troubled by his tendency to be distant-a tendency which is exacerbated by his involvement with NSA (which she knows nothing about). Despite a strong desire to preserve her marriage, she is determined to find out the truth behind her husband's seemingly inexplicable behavior. Series Lead; Baker: Mid 30's, any ethnicity. NSA agent. Smart, sexy and tough, responsible for "recruiting" Paul against his will. Despite her outwardly calm and professional manner, she harbors a secret tragedy which is hinted at in the pilot and will be explored during the series. She may also find herself, against her better judgment, attracted to Paul more than she should be. Series Lead; Wicks: Late 30's-Mid 40's, any ethnicity. NSA agent. A man with a good sense of humor and a bit of an attitude (ala Tommy Lee Jones), who thinks he is a stud. A company man in love with his job. He is in your face, intimidating, sees the world as black and white. Series Lead; Frank: Mid 40's. Kate's older brother, Paul's boss. He and Paul don't get along. Frank, an ambitious and successful management type, can at times be pompous and self-important, but he also genuinely cares for his sister, and is determined to protect her from what he sees as Paul's possible infidelity-not realizing that he has been targeted as a possible traitor by the NSA and Paul. Series Lead; Andrew: 16. Paul and Kate's son. A basically decent kid who has begun hanging out with the wrong crowd. He gets caught up in a drug bust with a friend in Mexico and frantically calls his dad when he ends up in a Mexican prison. Series Lead. (Posted: January 11, 2007)
Posted March 2007(Los Angeles, CA) - Title:
SPY (F.K.A. NSA INNOCENT), TV Pilot for FOX. CAST, Stana Katic, Jesse James, Billy Brown; EXEC PROD, Joel Surnow, Bob Cochran, Howard Gordon, Jon Cassar, David Ehrman; DIR, Jon Cassar; WRTR, Bob Cochran, David Ehrman.
Shoot Dates: April 2, 2007 (in Los Angeles). Breakdown-- Paul Fisher: Late 20s-Early 30s. Smart, thoughtful...and a brilliant engineer. He will be enlisted by the government, against his will to be a spy. He's clever enough to succeed, but he's no hero. He's an ordinary guy - who just wants to start a family with his young wife. Series Regular; Kate Fisher: Late 20s-Early 30s. Formally a corporate lawyer who got addicted to painkillers. Got into a car accident while under the influence and was disbarred. She just wants to get pregnant and start a family with Paul. Smart, warm...and a touch fragile. Series Regular; Laura Brooks: Late 20s-Early 30s. Roughly; a project manager on the same team as Barry and Paul; attractive, sexy, but slightly hard around the edges; is having an affair with married Barry. Series Regular; Frank Conroy: Mid 30s-Mid 40s. A V.P. at the corporation; a suit, not an enginee; ambitious, has a natural antagonism with the creators of the technology he sells. Series Regular; Barry Meyers: Late 20s-Early 30s. His best-friend; also an engineer, but much more manic and unpredictable than Paul; he can be charming one minute, angry the next; lives beyond his means and is paying for it with ill-gotten gains. Guest Star; Dr. Helen Fields: Over 40. Compassionate, slightly maternal. Fertility specialist. Recurring / Guest Star. (Posted: March 15, 2007)
TV.com has this on their site(maybe old and inaccurate, since it list Stephen Moyer ) : Originally on: FOX (60 min.)
Status: New Series Premieres: June 1, 2007
Show Categories: Drama, Action/Adventure
Stana Katic stars as Baker, an NSA agent who recruits Paul Fisher (Stephen Moyer), a normal family man as a spy against his will. Baker is described as a sexy, smart and tough woman in her mid-thirties.
This drama from Fox is created by Bob Cochran and David Ehrman.
20th Century Fox TV produces the show along with Real Time Productions. The show has been given a 7 figure put pilot by "Fox" network.