It's the last day of sessions here at the TCA press tour [1], and it's NBC's turn to hawk its wares. Just a few minutes ago, NBC Entertainment Co-Chairman Ben Silverman took the stage to clarify a few things about The Office [2] spinoff (and not-spinoff), the network's plans for late night, and more. Some highlights:

• First and foremost: The show in which Amy Poehler was recently cast [3] is not a spinoff of The Office. "Amy's character will never appear inside The Office world," Silverman said. Though the shows will be stylistically and creatively similar (in that Greg Daniels and Michael Schur will be behind both of them), "the show is not set up to emanate directly from The Office."
• There is still the possibility of such a spinoff, though. When Daniels and Schur were developing concepts, they came up with two, Silverman said: One that would start inside The Office and one that was completely outside of it. When it looked like Amy Poehler could be available, they put all their energy into pursuing her for the non-spinoff show, which made it the top priority. But the true spinoff could still exist, "maybe involving characters that are already inside The Office," Silverman said.
• As for details on either show? Not so much getting into those (including a title, a concept, or any other basics) — though there was a promise that Daniels, Schur, and Poehler would release more details soon. The one nugget of info is that because of Poehler's pregnancy, her show — which had been pegged for the post-Super Bowl time slot — will likely premiere in March instead. No idea what's going after the Super Bowl just yet.
• This season will feature "26 to 28 awesome episodes of Heroes [4]" — which we're finally getting some glimpses of [5]. "This 'Villains' storyline that [Tim Kring] has introduced is just awesome," Silverman said. "It's really compelling — just big, fun, accessible stuff."

Some more — including about the Jay Leno/Jimmy Fallon/Conan O'Brien transition — if you .

• Jay Leno's last show as the host of The Tonight Show will be May 29, 2009, with Conan O'Brien stepping into the chair on June 1. Conan's stint on Late Night will end sometime in the first three months of 2009, while the target for Fallon to appear on air is sometime around March or April. Fallon will prepare by doing online mini-episodes for a few months before the show launches.
• Meanwhile, NBC still hasn't ruled out finding a way to get Leno to stay, despite a story last week that quoted him saying he was "definitely done next year" [6] with NBC.
• Silverman's co-chairman, Marc Graboff, said NBC was committed to airing Friday Night Lights [7] no matter what — even if much of the audience has already watched on DirecTV or another way. (Graboff and Silverman also didn't accept that "another way" of downloading unlicensed versions of the show online might flourish, though, saying they'd be able to control it. We'll see about that.)
• Last year, NBC tried sci-fi Mondays with Chuck, Heroes, and Journeyman. This year, it's all about "a kind of male hero sandwich," Silverman said, with the Christian Slater-starring My Own Worst Enemy taking over the old Journeyman slot. Before Enemy premieres, though, the Friday night series Life will get a couple of airings after Heroes to try to reset the season and attract an audience.
• Little switcheroo in the Thursday comedy schedule: The new series Kath and Kim [8] will follow My Name is Earl, with 30 Rock returning to the spot after The Office at 9:30.

Source [9] and Source [10]