While no reason was given, I guess it's possible that the parties involved, Dominion and Fox News, have agreed to some sort of settlement, but that's just speculation on my part:
Delaware Judge Delays Start Of Dominion’s Defamation Trial Against Fox News
The judge did not cite a reason for the decision.
http://www.huffpost.com/entry/fox-news-dominion-trial-delayed_n_643c96aae4b0ac40918bdbd9

OCU