By Nicole Sperling
Updated May 30, 2010 at 05:37 PM EDT

Image Credit: Craig BlankenhornWith a significant drop for Sex and the City on Saturday and just mid-level earnings for Prince of Persia, Shrek Forever After is on track to win what looks like the slowest Memorial Day holiday weekend at the box office in a decade. It’s also the first time in five years a holdover release will capture the Memorial Day crown.

Perhaps those weak reviews on Sex really did do some damage to its box office performance. Despite the film’s B+ from Cinemascore, the sequel took in an estimated $10 million on Saturday, down from its estimated $13 million take on Friday. Its three-day gross stands at $32 million; its four-day total (it opened on Thursday) has reached only $46.3 million, far less than the $57 million grossed by the original two years ago.

Meanwhile, Prince of Persia took third place, but seemed to suffer from an overall lack of interest. The Jerry Bruckheimer epic adventure starring Jake Gyllenhaal and based on the popular video game just crossed the $30 million mark for its first three days of release. It received a B from Cinemascore and seems to be resonating best with boys under 18.

Shrek Forever After hit the top earning close to $17 million on Saturday, for a three-day total of $43.3 million. (Seven percent of its total came from IMAX screens.) The fourth chapter in the billion-dollar franchise seems to be making up ground after not breaking any records last weekend, climbing to $133 million in 10 days. The final chapter is still tracking more than $50 million behind Shrek the Third and it’s unlikely it will be able to catch up.

The three releases at the top are a far cry from last year’s Memorial Day frame, which boasted a three-day $54 million gross from the Night at the Museum sequel and $42 million from the opening frame of Terminator Salvation. The weekend is likely to be down more than 14% compared with the holiday weekend in 2009.

The rest of the top ten was dominated by well-playing holdovers that, with the exception of MacGruber, fell less than 50% for the weekend. Marvel Studio’s Iron Man 2 claimed fourth place with an estimated $16 million, a decline of only 39 percent for the frame. In its four weekends of release, the superhero actioner has earned $274 million, outpacing the original by over $15 million. Universal’s Robin Hood fell 45 percent, earning another $10.3 million in its third weekend in theaters, for a cume of $86.2 million. It’s not certain the expensive film from director Ridley Scott and actor Russell Crowe will even cross the $100 million mark.

Summit Entertainment’s Letters to Juliet is holding its own despite the box office challenge from the Sex and the City women. The Amanda Seyfried-starring romance dropped a scant 34 percent from last weekend, grossing $5.9 million for the three days, for a cume of $38.1 million. Seventh place went to Fox Searchlight’s Just Wright. The Queen Latifah-starrer earned another $2.2 million to put its three-week gross at $18.2 million. Twentieth Century Fox’s Date Night just keeps on trucking. The film is hanging in the top ten after two months of theatrical release, adding another $1.75 million to get a little closer to the $100 million mark ($93.4 million).

Poor MacGruber. The Relativity Media-financed comedy from Saturday Night Live producer Lorne Michaels lost more than 63% of its value from its weak opening weekend, collecting just $1.5 million for three days to land in ninth place. The film, starring Will Forte, has brought in just $7.5 million after two weekends of release. How to Train Your Dragon clings to the tenth spot in its tenth weekend with another $1 million. Overall, the Dreamworks Animated flick has generated over $212 million.

Have a great weekend and enjoy the rest of your holiday break!