That's a fun hypothesis. The irony of the study coming out of something named for Murrow is worth posting by itself.
The real issue of polarization is that it is happening especially among elites. I've even seen it argued it is pretty much only happening among elites. It is for sure more pronounced among the policymakers. So, I am skeptical of the claim that television would cause that form of polarization. I would rather blame an increase in party power or radicalization (think Tea Party). Television is for the masses, and deregulation has affected them for sure, but that isn't generally the polarization being discussed.
Yesterday, I asked myself what anyone stands to gain from paying heed to "breaking" news. Short of life-threatening events thwarted by instantaneous news (I'm drawing a blank here... Edit: eh, maybe something large scale like 9/11), there isn't a benefit to the average consumer, aside from satisfying their apparent need of constant stimulation. I've found it much more beneficial to read well-researched articles from as many sources as possible. But "well-researched" is impossible to pull off when a event is still in the process of playing out. We need time to frame it in the greater perspective.