Sony’s “This Is It” was one of several films doing more biz than expected on Sunday as moviegoers quickly recovered from Halloween and headed for the multiplex.“This Is It” saw its domestic five-day opening grow by a healthy $1.9 million to $34.4 million. The film grossed $8.3 million Sunday instead of the $6.4 million initially estimated by Sony. In fact, Sunday turned out to be the top-grossing day for “This Is it,” directed by Kenny Ortega and featuring Michael Jackson rehearsing for his London concerts. “This Is It” did slightly more overseas than initially projected, with $69.5 million vs. $68.1 million. Sony and other distribs had been cautious about estimating Sunday traffic at the domestic B.O., worrying that Saturday’s Halloween festivities might stretch into Sunday and affect moviegoing. But that wasn’t the case, even for family-oriented titles. Warner Bros.’ “Where the Wild Things Are” saw nearly $1 million more than projected, putting the weekend haul at $5.9 million. Summit Entertainment’s toon “Astro Boy” did $500,000 more than projected for a total weekend gross of $3.5 million. That was good enough for No. 7 in the frame instead of No. 8, as estimated on Sunday. Universal’s Vince Vaughn comedy “Couples Retreat” also benefited. Laffer did $400,000 more than estimated for a weekend tally of $6.5 million.