The Writers Guild of America East has expanded jurisdiction by more than a dozen cable shows over the past year, including “Johnny and the Sprites,” “The Naked Brothers Band,” “Important Things With Demetri Martin,” “Best Week Ever” and “Night of Too Many Stars.”

“Organizing work that is not covered by guild contracts is not optional; it is essential,” said WGA East exec director Lowell Peterson in a message sent Friday to the guild’s 4,000 members. “The WGA East has been quite successful in signing shows outside the networks and major studios. The union has signed 13 significant cable shows to the 2008 MBA — including shows on Comedy Central, VH1, Here, Disney Channel, ESPN, MTV2, Ion and the History Channel — plus three made-for-new-media programs, seven low-budget feature films and five foreign-produced projects.”

Peterson also noted that the 100-day feature-primetime strike in 2007-08 had united the membership of the WGA, which includes the 8,000 members of the WGA West, and placed the guild at the forefront of Hollywood unions’ new-media battles.

“People knew the Internet and other digital technologies would reshape our industries, but no one really knew where the writers would fit in,” he added. “We still do not know exactly how this thing called ‘new media’ will ultimately affect writers. More and more work that was initially presented on television or in theaters will be made available online — for streaming or downloading, with or without advertising.”

New-media compensation and jurisdiction were the WGA’s key strike issues during the bitter work stoppage, and the current three-year pact expires in May 2011. Peterson issued a note of optimism about the industry’s ongoing need for writers.

“People are working, creating great stories, making people laugh, imparting news and information,” he said. “Although many of the managers we see across the bargaining table don’t seem to care about quality, I think ultimately guild members will prosper in the new environment; people want great stories, written well.”

Peterson sent the message as part of noting his one-year anniversary after succeeding Mona Mangan, an often- abrasive figure within the showbiz labor arena during her 25 years at the helm. Peterson, a veteran labor attorney prior to taking the WGA post, didn’t mention Mangan by name but noted that WGA East’s operations “were not in good condition” when he started and that he’s worked to defuse internal tensions, implemented fiscal controls, cut legal expenses and improved transparency of operations.

Peterson also noted that the WGA East contracts for ABC and CBS newswriters expire early next year. Both deals were reached by Mangan more than a year after they expired.

“We have already started to build mobilization networks at these shops,” Peterson said. “The previous negotiations took years to complete, and some members remain uncertain about the guild’s commitment and capacity. Therefore, it will be particularly important to engage members in the process.”

The message was issued a week after WGA West president Patric Verrone issued an upbeat assessment of the guild’s organizing efforts, citing gains in cable and new media. The WGA West has inked contracts on two dozen cable skeins, including 15 on Comedy Central, and made deals with 26 companies in new media, 44 interactive agreements plus deals on 15 low-budget features and three foreign-produced projects.