On Friday evening, MSNBC host Keith Olbermann, an outspoken champion of liberal causes and Fox News critic, sent the Internet abuzz with the surprise announcement that he was broadcasting his last show of "Countdown."

Questions have cropped up about whether Olbermann and MSNBC would part ways ever since the network suspended its top-rated host for making campaign donations to Democratic candidates. "There were many occasions, particularly in the last two and a half years, where all that surrounded the show--but never the show itself--was just too much for me," Olbermann said in his sign-off on Friday, while also praising his show for its "anti-establishment" positions.

The agreement between Olbermann and NBC prohibits Olbermann from hosting a television show or commenting publicly on his departure for an undisclosed period of time. In the meantime, speculation abounds about why Olbermann's eight-year run with MSNBC has suddenly ended. Was he fired? Did he quit? Did Comcast, which is poised to acquire NBC Universal, play a role?

  • Olbermann's Fans Are Blaming Comcast, explains Bill Carter at The New York Times. They accuse Comcast "of forcing him out for political reasons," Carter says, adding that "several of Comcast's top executives have been financial supporters of Republicans." But Carter cites one Comcast executive as saying the company "dreaded the prospect of being blamed if Mr. Olbermann were to quit soon after the takeover." Comcast denied any interference with NBC Universal's news operations in a statement.
  • This Was About Comcast And Money, claims TMZ, quoting unnamed sources. The Hollywood gossip site says Olbermann's agent couldn't convince NBC's executives to pay his client more money, and that Comcast "wanted Keith gone because he was 'a loose cannon that could not be controlled.'"
  • Break-Up Was Mutual, asserts The Daily Beast's Howard Kurtz. "Olbermann has been on the defensive about his intense and sometimes incendiary style" in recent months, Kurtz explains. A source tells Kurtz that Comcast had nothing to do with the move. But if Olbermann "concluded that he would no longer have the independence he craved in the more buttoned-down Comcast era," Kurtz concludes, "it is unlikely that anyone in the NBC executive suites tried to talk him out of it."
  • Appears Like Olbermann Was Fired Abruptly, says Greg Sargent at The Washington Post. He points out that Olbermann, looking "shell-shocked," explained that he had "been told" this was the last edition of his show during his sign-off on Friday.
  • Olbermann Is Victim of Own Success, claims Salon's Steve Kornacki. MSNBC's lineup now includes rising stars like Rachel Maddow, Ed Schultz, and Lawrence O’Donnell, Kornacki notes: "Now that they've built a loyal prime-time audience of left-leaning viewers, NBC's executives may simply feel that they can afford to be rid of Olbermann and all of the headaches he brings with him."
  • No He Isn't, responds Ed Morrissey at Hot Air: "Olbermann may have set the tone for MSNBC's prime time, but that didn’t come because he took over the hour of programming, commando-style, and refused to leave the set until MSNBC decided to get partisan. MSNBC made that decision themselves when they hired and then rehired Olbermann."
  • This Is About Tension At Heart of Cable News, argues Politico's Keach Hagey: Olbermann's "departure reveals the problematic structure of the current incarnation of cable news, in which bombast, opinion and outsized personality get ratings, but these same qualities can make talent almost impossible to manage."