I have heard the word glitterati three times in the last week ('...all the Hollywood glitterati were there ...'). I can't remember the last time I heard anybody use the word literati in any context. The one word, derived from the other, has now supplanted it. Eventually the latter will simply wilt to nothing, and the origin of glitterati will become a philologists' talking-point.
A related thought: did Coleridge coin the term clerisy because he, with a poet's ear, wanted it to be haunted by the word heresy? A buried critique within the word itself?