The NewsHour Goes High Definition

This is false. Most High Definition / Digital channels are still required to broadcast with closed captioning. The NewsHour and PBS will continue to broadcast the program with closed captioning. New "digital ready" and ATSC tuner-supported television sets are required to, and do support, closed captioning.

This is not true. In fact, all broadcasts originating in the United States must, by law, be captioned as of a couple of years ago and all TV's sold for the past several years in the U.S. must be capable of displaying closed captioning. The closed caption format is different for HD but is definitely there. You may have to do things differently on an HD set (i.e., menu options) to display the captions but there are available.