By which I mean an excellent, effective Christian apologist of a new kind and potentially broad constituency?
Well, probably there never will be another Lewis, as a package; but in terms of apologetics, Givens comes closer than anyone I can think of with The God who Weeps - co-written with his wife Fiona.
What I get from the Givens's book is the same kind of freshness as I find in Mere Christianity (and which is so lacking from later attempts to emulate MC) - it results from the capacity to rethink faith from the ground up, based on premises which the author personally finds relevant and convincing, together with a strong and likeable literary persona.
The twist, of course, being that Givens is what might be termed a Mere Mormon, and furthermore one who has stepped away from any worries about convincing mainstream Christians that they ought to include Mormonism, but who has instead focused on clarifying and explicating Mormonism's distinctive qualities with most relevance to the concerns of modern times.
I made this connection while re-reading God who Weeps and after reading the blog Dawning of a Brighter Day:
I have no idea whether Givens is indeed the Mormon CS Lewis, since I don't know enough about his Mormon rivals - but whatever his status in the LDS community, Givens could well become a Lewis-ite figure for Mere Christians, if only they could approach his work in a positive spirit.