NBC insiders are buzzing that Jimmy Fallon is being positioned to be the net’s next big late-night star. Since the NBC-Comcast merger, the succession plan in the event Jay Leno leaves is built on Fallon, whose current show is on right after Leno’s. “Jimmy is a lot closer to [taking over from] Jay than Conan [O’Brien] was,” an insider said. “Jimmy is the future.” On the other hand, MSNBC host Keith Olbermann‘s fiery antics won’t likely be received well by the new bosses. “It’s predicted that Comcast will not have the same tolerance for Olbermann that [former NBC president] Jeff Zucker had,” a source said. A rep for NBC had no comment.