There's the casting of 'Matrix' star Carrie-Anne Moss in a multi-episode arc as Gertrude Verbanski, the head of a private espionage agency that competes with Chuck's new firm. A woman as tough, competitive and weapons-obsessed as Gertrude naturally appeals to John Casey.
"What we wanted to do this season is really kind of open up [Casey] to a new romantic relationship, and we thought we needed someone as badass as him," Fedak said. "Carrie-Anne seemed like the perfect fit."
But during the final season, there trouble among the Buy More staff -- Jeff and Lester, otherwise known as the not-quite-legendary rock band Jeffster, hit a rough patch in their relationship, and I learned that one of them even goes to jail. But could an 'Office' gig be in Jeffster's future? It's a long shot, but if it happens, it could be one of the funnest crossovers of the season.
Fedak said that, as we learned at Comic-Con, this season Jeff and Lester's musical and personal relationships enter 'Behind the Music' territory. All is not well between them, to put it mildly.
"Like late Lennon-McCartney, there's bound to be a point where that relationship really needs to come to a head," Fedak said. "So we have a lot of dramatic, exciting changes for Jeff and Lester -- that may lead to one of them winding up in jail."
He wouldn't say which one of the duo ends up behind bars, but I asked if the jail stint involved involuntary detox for the prisoner in question. "You're thinking about the wrong person," Fedak said.
"It's the absolute one who should not end up in jail who winds up in jail," Fedak added. All those hints leed me to think the jailbait is Lester, but the cagey Fedak wouldn't say. Still, he sounded excited to do another prison-based episode of the show.
"We've done a couple of prison episodes, but I didn't feel I got it out of my system, so we're going to do more," Fedak said. Naturally, there will be jailbreak, right?
"It's the 'Chuck' show," Fedak said. "You can pretty much guarantee there will be some kind of a jailbreak."
At the party, I tracked down Scott Krinsky and Vik Sahay, who play Jeff and Lester, to get more details about the Jeffster turmoil.
"I think I can safely say, maybe there's some relationship counseling in the future," Krinsky said. What?
"We're going to get to the root of Jeff's mental condition," Krinsky said. "There could be some revelations that surprise you." And it sounds as though what's uncovered ends up causing the Jeffster breakup.
At the party, Krinsky and Sahay happened to be sitting with Angela Kinsey, who plays Angela on 'The Office.' The actress said she's going to pitch the actors for an upcoming episode of the long-running comedy.
"They have a story line this year in 'The Office' where the guys in the warehouse win the lottery and they quit. Right here," she said, pointing to Krinsky and Sahay, "two new warehouse workers."
"And what's amazing is this year, we get James Spader" on 'Chuck,' Sahay joked.
In a more serious moment, Sahay said there's definitely an "emotional" feeling on the set of the show during the final season. Both actors said it was difficult to think about the show ending.
"I will very much miss working with Vik. I don't know where I will find chemistry like this again," Krinsky said.
Well, at least the show appears to be going out with a bang. We learned at Comic-Con that Mark Hamill will guest star as a villain in the show's season 5 premiere, and I look forward to seeing what kind of chemistry the Gertrude Verbanski-Casey relationship produces.
Let's hope for some ace Jeffster performances (perhaps 'Jailhouse Rock'?) before the show closes up shop for good. And as for Kinsey's idea, I not only endorse it, I think once 'Chuck' wraps up for good, the former Buy More employees should make appearances on every quality comedy out there (I wonder if the garbage collection department is hiring on 'Parks and Recreation'?).
For more on 'Chuck,' check out our Comic-Con coverage.
Follow @MoRyan on Twitter.