I work for an NBC affiliate and woke up to my phone going nuts with alerts about the incident and there was network coverage most of thursday I think. CNN will most likely cover it until we go to war with russia or something since they covered MH370 for months...
For the most part, it seems like NBC News is at least trying to keep with facts that are being gathered first hand instead of speculating, which is slow due to the rebels in that area hindering an investigation into the flight (which honestly, rebels probably shot down). At least earlier when I was at work, there was only one American citizen confirmed on the flight that was also Dutch.
It's a horrible situation all around that so many people lost their lives for absolutely no reason in an instant just because their flight going through a zone, that in all honesty should have been avoided due to the deteriorating conditions in the area.