People involved in the talks suggested this week that one or both deals may be imminent, but that may not be enough to ensure a summer start. Todd Gold, the editor in chief of XfinityTV.com, Comcast’s television news site, said it was becoming clear that the show was “right on the cusp of going one way or the other.”

“By now, the writing staff should be humming along, maybe about a month or more into work for a summer premiere,” he said. “Unless Weiner is secretly manufacturing outlines in preparation of some crazy all-night writing sessions with his staff, it might be time for fans to grow concerned.”

“Mad Men” has always enjoyed an extraordinarily passionate fan base. Last month the sisters Deborah and Roberta Lipp, the makers of a fan Web site for “Mad Men” called Basket of Kisses, promoted a petition calling on AMC and Lionsgate to bring the show back in 2011. But now they are mostly resigned to a 2012 return date.

“Naturally, I’m sad, upset, frustrated and disgruntled,” Deborah Lipp said.

Roberta Lipp added: “The most highly acclaimed show on television and it can’t get back on the air? Unacceptable.”

One question has continued to hover over the negotiations: How many more seasons of “Mad Men” should there be? It is understood that AMC has the rights to “Mad Men” through Season 5 but that it wants to renew the show through at least Season 6, with Mr. Weiner on board. Mr. Weiner, whose contract ended after Season 4, has never definitively answered the how-many-seasons question. He did not respond to a request for an interview this week, but he told Entertainment Weekly in January that “I want the show to go on and on and on until it has worn out its welcome with viewers, and we can’t think of anything more for the characters to do.”