Hard to get it shorter than that, but in case the link dies:
Markos Moulitsas of the Daily Kos used to be a regular guest on Olbermann's MSNBC show (and other shows as well). Then he wasn't. Olbermann gave him a few minutes at the end (and over the end) of the show to explain. Moulitsas says that back when Joe Scarborough was trying to help the White-House-offered-Sestak-a-job non-story going, Moulitsas tweeted about the Scarborough intern-died-in-his-office story that never took off. According to Moulitsas, Scarborough complained and Moulitsas was no longer allowed to be a guest on any of the MSNBC shows. Part of the point being made was that Scarborough had for-crap ratings and Olbermann had quite good ratings.
Lots of secondary coverage, obviously. The twitter feud and the fallout from it have apparently been fairly widely known (I hadn't noticed but I can find coverage from a while ago). The right wing media is holding its line (No One Could Possibly Believe He Had Anything To Do With Her Death). They're good at that.