Veteran NBC News correspondent Peter Alexander is joining MS NOW , the latest example of the Versant-backed outlet trying to make an aggressive play in hard news, as well as the opinion programming for which it is best known. Alexander was, until Saturday, NBC News’ chief White House correspondent and a co-anchor of its Saturday “Today” broadcast, an ambitious and logistically challenging set of assignments. At MS NOW, he will anchor the network’s weekday 11 a.m. slot, left open in a recent