STORY NOW UPDATED WITH VIDEO OF OLBERMANN'S STARTLING, UNEXPECTED ON-AIR FAREWELL, WHEREIN HE SAYS HE WAS TOLD TO LEAVE. Breaking News: Keith Olbermann Announces At End of His Show Tonight That He's Leaving MSNBC, Effective Immediately TVWeek

Viewers were shocked this evening when Keith Olbermann announced he was told this would be his last show and that he'd be leaving MSNBC.

As you can see in the video below, Olbermann told viewers near the end of his show on Friday, Jan. 21, 2011:

"I think the same fantasy has popped into the head of everybody in my business who has ever been told what I have been told: This will be the last edition of your show.

"You go directly to the scene from the movie ‘Network,’ complete with the pajamas and the rain coat and you go off on an existential, otherwordly, verbal journey of unutterable profundity and vision.You damn the impediments and you insist upon the insurrections and then you emit Peter Finch’s guttural resonant “So” and you implore, you WILL the viewer to go to the window, open it, stick out his head and yell---well, you know the rest.”

The rest is that the Finch character in "Network," named Howard Beale, instructs everyone to yell "I'm mad as hell and I'm not going to take this anymore!"

After Olbermann's show ended MSNBC then issued the following statement: " MSNBC and Keith Olbermann have ended their contract. The last broadcast of "Countdown with Keith Olbermann" will be this evening. MSNBC thanks Keith for his integral role in MSNBC's success and we wish him well in his future endeavors."

It's the second major development involving TV made since Comcast gained government approval of its NBC Universal deal earlier this week. The first development was yesterday's announcement by the President of NBC Primetime, Angela Bromstead, that she was leaving the network.

An NBC source familiar with the situation claimed that though Comcast was informed about Olbermann's leaving MSNBC, Comcast had nothing else to do with the move. This source also claimed that this was not a sudden decision, and that discussions about Olbermann's departure had been on-going for some time.

However, a number of other reports, including ones by TMZ and are saying just the opposite, that Olbermann's departure was prompted by Comcast's pending acquisition of NBC Universal.

UPDATE: Comcast itself later issued this statement: “Comcast has not closed the transaction for NBC Universal and has no operational control at any of its properties including MSNBC. We pledged from the day the deal was announced that we would not interfere with NBC Universal’s news operations. We have not and we will not.”

The controversial Olbermann's program was MSNBC's top-rated show.
Clip of Olbermann announcing his leaving show and MSNBC