Leading the TV pack in total viewers, CBS reliably has fewer programming holes than any other network, but that didn't stop CBS Entertainment President Nina Tassler from discussing some big potential projects at the Television Critics Association press tour on Wednesday (Jan. 14).

One of CBS' high profile series candidates is a long-mentioned spin-off to the Tuesday night stealth juggernaut that is "NCIS." Details on the spin-off are scarce except for the amusement in the rare example of a spin-off of a spin-off.

"It’s happening," Tassler promised. "We’re doing it. We’re waiting for the — we’ve seen an outline. We’re in great shape, and we’re just waiting to get the script, but we’re going to cast, and we’re going to shoot."

Tassler continued, "Remember how 'NCIS' was developed. It’s still following in that tradition. I mean, 'NCIS' was an episode of 'JAG,' and this spinoff will be an episode of 'NCIS.'"

With "NCIS" successfully holding ground against "American Idol" on Tuesday nights and serving as a launching pad for "The Mentalist" this season, it's no wonder CBS is hoping to expand the brand. 

The network is also hoping to turn musician/celebrity boyfriend John Mayer into a brand.

[More after the bump.]

"[W]e’re actually pretty close to closing our deal," Tassler said of the Mayer show. "It will be a musical, variety, sketch show, yeah. It’s being developed now."

Asked for more details, Tassler added, "[W]e’re looking at a couple of things. It’s sort of a pilot. It could be for a series of specials. It could be just for a series. I mean, we’re just going to shoot the pilot now, see what we have, and make a decision after that."

One show that won't be in CBS' plans going forward is "Swingtown," which attracted a small, but dedicated following in its summer run.

"It was a terrific show and, look, I’m happy to report it ended up on over a half dozen Top 10 lists from 2008," Tassler said. "So at the end of the day, I think the show was well-executed. It was well-received. The performances were great. The writing was great. And in many regards, I think that show was also a victim of the strike, but it was a risk, and we took it, and we’re proud of it and certainly would take it again."

Asked point-blank, though, if the '70-set couple-swapping drama was done, Tassler didn't hesitate.

"No. We’re not going back to 'Swingtown' right now."

Tassler gave a similarly simple explanation for the failure of "The Ex List," the network's lone fall disappointment and speedy cancellation.

"I still love the concept for the show," Tassler. "I think that it sort of failed in its execution. Ultimately that is when a show doesn’t take off or doesn’t resonate. I think people liked the concept, but it never found its traction. It didn’t find its pulse. So that would be my observation."