Tina Fey and Amy Poehler’s “Baby Mama” pulled in $18.3 million in its opening weekend at the box office, good for the top spot (in what’s sure to be the last sub-$20 million opening weekend for awhile). MP users turned in a near-perfect prediction for “Harold & Kumar Escape from Guantanamo,” which registered a $14.6 million debut. “Forbidden Kingdom” fell to third with $11.2 million, followed by “Forgetting Sarah Marshall” and “Nim’s Island.”

On the Billboard 200 the emancipation of Mimi continues, as Mariah Carey landed at No. 1. Leona Lewis, Miley Cyrus, and Lady Antebellum filled out the top five, while R.E.M. slid from fifth to ninth in only its third week out. Taylor Swift crept back in to the top 10 in her self-titled album’s 78th week on the charts.

It appears total domination of the network ratings just isn’t good enough for FOX. “American Idol” continues to crush the competition in the Nielsen ratings. Still, the network is performing online research to determine how the show might be improved.

Julie Andrews’ memoir “Home” is No. 2 on the NYT non-fiction list. It covers “from birth to being cast as Mary Poppins.” Fans of the book can expect a sequel in 2-3 years. Speaking of sequels, the 9th book in Alexander McCall Smith’s Ladies’ Detective Agency series enters the fiction list at #3.

Teen slasher remake “Prom Night” killed at the box office, pulling in nearly $23 million to top meager competition from Keanu Reaves in “Street Kings” ($12 million). Everything’s coming up aces for “21,” which added $11 million to its box office take for a total of $63 million through three weeks. “Smart People” opened back at 7th, with a little over $4 million.

George Strait’s “Troubadour” and R.E.M.’s “Accelerate” ran 1-2 on the Billboard 200. Van Morrison barely cracked the top 10 with “Keep it Simple,” while the soundtrack for “Alvin and the Chipmunks,” which came out four months ago, jumped back in to the top 5.

Yet again “American Idol” was the most watched show on television this week. Twice. “CSI” managed to unseat the “Dancing With the Stars” results show for 4th place in what was a strong week for CBS. But don’t break out the party favors just yet, Les Moonves: Goldman Sachs reiterated its sell rating on CBS. It seems the network has a little problem the analysts like to call “limited appreciation potential.”

Notable news from the New York Times bestseller lists: Julie Andrews is somehow still relevant, Kurt Vonnegut has a new book out despite being dead, and Jose Canseco is not only a two-time bestselling author but a quality individual.

If George Clooney really is the “last movie star,” as Time breathlessly asserted, Hollywood may be in trouble. Clooney’s “Leatherheads” limped to a second place finish in its opening weekend, behind Kevin Spacey and Co. in “21.” Kid flick “Nim’s Island” debuted in third with $13.3 million, “Horton Hears a Who” pulled in $9.1 million to bring its 4-week total to $131 million and change. “The Ruins” opened in fifth with $7.84 million.

DAY26’s self-titled album debuted at #1 on the Billboard 200, trailed by Panic at the Disco (now sans exclamation point), Counting Crows, and Danity Kane. The Raconteurs hit the charts at #7 with their hastily-released second album, “Consolers of the Lonely.” The surprise early-release strategy didn’t work out for Gnarls Barkley, which failed to crack the top 10 in either of its first two weeks.

Mariah Carey and Madonna, not exactly pals, were forced to share the spotlight last week in a delicious bit of irony. Mariah’s 18th No. 1 single, “Touch My Body,” pushed her past Elvis and within striking distance of the Beatles’ 20. “4 Minutes” became Madonna’s 37th top 10 single, also moving her past The King.

Good news for FOX competitors: “American Idol” didn’t take the top 3 spots in the Nielsen ratings for the first time in ages. The bad news: FOX only ran two episodes last week. “Dancing With the Stars” and its results show pulled in strong ratings to finish 3rd and 4th, respectively.

Jonathan Kellerman sits atop a slew of newcomers on the New York Times fiction list. On the non-fiction side of things, copies of “Brett Favre: The Tribute” are flying off the shelves. They’re expected to go up in value just as soon as Favre unretires.