Since going public with their happy news in April, the pair have been unapologetically giddy. On Oct. 3 Parker and Nixon spent two hours at a Manhattan Barnes & Noble signing Amy Sohn's new book Sex and the City: Kiss and Tell, an insider's guide to the making of the show. Parker, clad in a low-cut sundress that showcased her newly ample bosom, modeled her swollen belly for some two dozen photographers and engaged in pre-baby girl talk with fawning fans. "You look amazing!" gushed advertising executive Tina Allan, 34, of Long Island when she reached the front of the two-block-long line. "That's so sweet of you," Parker responded, then raised her hand above her belly. "But don't look from here down. Honey, you don't know what's going on from here down!" To others, she confided, "I'm very excited." Asked if she was ready for the baby, she allowed with a nervous giggle, "I think so . . . " Even the more reticent Broderick fessed up in a June TV interview with Entertainment Tonight, "I am excited about the baby."

"They're going to be fantastic parents," says Kristin Chenoweth, 34, Broderick's costar in a remake of The Music Man that will air on ABC in February. "The kid'll be in stitches all the time." During the film's three-month shoot in Toronto, Chenoweth witnessed Broderick's deft touch with the younger members of the cast. "Kids love him," she says. "He makes them laugh. He treats them like little adults."

Broderick has had ample practice with his two nieces and two nephews, who range in age from 5 to 16. His sister Janet Broderick Kraft, 46, an Episcopal minister who officiated at the couple's wedding, recalls how, when she was trying to decide between two nursery schools for her 5-year-old daughter Hannah, Matthew took the time to visit both before weighing in with an opinion. "He is so loving with the children and so caring when the kids are sick," she told PEOPLE in April. "He loves to play with them."

As for Parker, if her pregnancy is any guide, her baby will have to keep up with her -- not the other way around. "She is the most fantastic pregnant woman I've ever seen," says Huffman. "She's going to be a highly energetic mother." To illustrate, Huffman trots out the Labor Day party that the celebrity duo hosted at their new house in Bridgehampton, N.Y. While Broderick flipped burgers, Parker attended to their eight guests. "She was hugely pregnant and didn't need any help," says Huffman. "She had the energy of five people."