Delta says it is adding its new lie-flat business class seats to all 747s, to match the product already available on the line's 777s and most 767s. More and more, flat-bed seats are becoming the standard for international business class.
Most reviews I read from frequent business class travelers is that real lie-flat "beds" are far superior to the big-recline or lie-outstretched-at-an-angle seats that had been the previous norm.
Given that almost all eastbound transatlantic flights, all eastbound and many transpacific flights, and almost all flights to and from the South Pacific and South America are overnights, lie-flat seats should be a big advantage for the lines that offer it. Some major airlines—including American, Lufthansa, and Singapore—that haven't yet fully installed lie-flat seats are likely to find some of their best customers deserting them for superior products elsewhere.