Showtime entertainment president David Nevins is shaking up the next seasons of Dexter, Nurse Jackie, and The Borgias (and possibly Weeds, too — permanent changes).

Talking to critics at the network’s press-tour event in Pasadena, the executive (who took over as the network’s programming chief in late 2010) said there’s some changes coming to some of the network’s most popular shows.

But first: Some premiere dates! Nurse Jackie, The Big C, and The Borgias will be back on Sunday, April 8.

– On Dexter: Nevins defended the controversial incest story line. “I’m aware there’s a certain taboo, even though they’re not genetically related,” Nevins said of Deborah’s brother-loving urges on the show’s recent sixth season. “It’s something that’s been building for a number of years. It’s an idea that’s informed how they’ve done that show for a long time.”

Nevins also stuck to his previous comments to EW.com, that the show is expected to conclude after the eighth season, barring any unexpected creative detours. As for last season’s big reveal in the finale — where Deb catches Dex in the act of executing a serial killer — Nevins said the reveal will have a major impact on the show. “I’ve been pushing to shake up the formula a bit,” he said. “There’s going to be fundamentally different dynamics now. It’s time to shake up Dexter so he’s not just a lone wolf.”

– After the panel, Nevins was asked if this summer’s Weeds will be its final season: “It’s a real possibility.”

– Yet viewers shouldn’t necessarily expect Nurse Jackie to end this year, Nevins said. “I wanted her to start facing some consequences of her actions, and she does in a big way,” he said. “She’s absolutely not in the same place as she is in the last seasons. The feel of the episodes is tweaked.”

– On The Borgias, season 2: “It’s a bigger show in season 2. It’s got more action, it’s going in more directions.”

– And breakout hit Homeland? No changes necessarily. But here’s a season 2 hint: “Brody and Carrie [relationship-gamesmanship] have only just begun. There’s an enormous amount unresolved and that will be a certainly be an issue in season 2.”