By Michael Ausiello
Updated March 17, 2010 at 01:18 PM EDT

Image Credit: Bob D’Amico/ABCEntertainment Weekly intern Vlada Gelman is covering PaleyFest ‘10 for The Ausiello Files. Here’s her report from last night’s Castle panel.

Bang, Bang: We were treated to a screening of Castle‘s March 22 episode, the first half of a two-parter guest starring Dana Delany. Nathan Fillion’s old Desperate Housewives costar plays a smart FBI profiler who comes into the picture to help catch a murderer who’s obsessed with Nikki Heat. Castle is awestruck by her and her fancy FBI equipment, which doesn’t make Beckett too happy. But never fear, Beckett and Castle fans. Feeling responsible for putting Beckett in harm’s way, Castle takes it upon himself to protect her. Let’s just say there is wine and pancakes involved and an interrogation by Esposito and Ryan.

No Butt’s About It: Never one to be less than charming and hilarious, Fillion fit the producers’ criteria for playing the mystery novelist. “Castle is a guy who is incredibly charming and that’s not something you can fake,” said the show’s creator, Andrew Marlowe. Showing off that humor, Fillion described his character as “not a hardass… with a hardass,” which led costar Tamala Jones, who plays medical examiner Lanie, to reveal that she has a habit of grabbing his butt. Fillion’s onscreen daughter, Molly Quinn (just 16-years-old!), singled out Fillion as the actor most like his character, except Fillion is even less mature and likes to put rockets on scooters.

Will They or Won’t They?: “Their relationship, like any relationship, will be prone to complications,” Marlowe said of Beckett and Castle. The producers would like to keep a sense of mystery and not rush into anything, which suits Stana Katic just fine. “I think there’s nothing sexier than swordplay,” she said. But Beckett isn’t all about Castle. Viewers will learn more about her life before Castle came into the picture.

Bromance and Backstories: Seamus Dever and Jon Huertas, who play Detectives Ryan and Esposito, respectively, are just as close in real life as they are on screen. Dever is even helping Huertas install some floor tiles. The pair, along with Jones and Ruben Santiago Hudson’s Captain Montgomery, may be getting more screen time soon. “We’ve been working to open up our supporting cast,” Marlowe said. There’s an Esposito-heavy episode coming up and even the chance of romance with Lanie, who may have a medical mystery on her hands.

Who’s Your Daddy?: While we won’t find out who Castle’s father is anytime soon, Fillion does have someone in mind for the part. “I’m voting for Christopher Walken playing himself,” he said.

Reading Is Sexy: As previously reported right here, Dancing With the Stars‘ Tom Bergeron plays a murdered late night talk show host in the April 13 episode “The Late Shaft.” He also hosted the panel and revealed that his character will be shilling the paperback release of Castle’s novel Heat Wave, which comes out July 27 in the show and in real life. ABC’s synergistic promotion of the show will continue with the release of Naked Heat in the fall, which came as a surprise to Katic. “I didn’t know that was the title,” she said.

It’s All Cyclical: With the upcoming redos of The Rockford Files and Hawaii Five-O, it’s hard to imagine that ABC was once weary of the show being compared to series like Moonlighting and Murder, She Wrote. According to executive producer Rob Bowman, when Castle first launched, ABC even sent the producers a letter saying not to mention Murder, She Wrote, but the press kept bringing it up in interviews.

Must List: What does Fillion want to do next season? “Drive,” he said.