From the New York Times:
The discussions between Ebersol and Comcast executives apparently came to a head in a meeting Thursday morning. By 10 a.m. Mr. Ebersol had scheduled a meeting to tell his staff he was stepping down.
Mark Lazarus, president of the NBC Sports Cable Group, will replace Ebersol.
What does this have to do with MMA you ask? Ebersol has long been a road block for MMA programming to make it on to the network having gone on record about his disgust for the sport (can't find the quote since "Ebersol resigns" stories are flooding Google right now). Now that he is gone, the long-rumored potential UFC deal with NBC is much more of a possibility.
In addition, the man replacing Ebersol is president of the NBC Sports Cable Group, which means he also oversees Versus. In my opinion, the stage is set now for the UFC to make a deal with NBC and I foresee it happening this year.