Ho hum, really ooooooooollllllddddd news!!
This has been pointed out about several parts, Chevy originally intended today's ZL1 to be the Z/28, I think the uproar from the Z/28 "purists" (of which I'm one), Z/28 "old geezers" (again, of which I'm one) on many forums that either owned or knew the first gen. Z/28 inside out were lambasting Chevy for wanting to name an over two ton behemoth that had an engine that was not naturally aspirated and calling that a Z/28. Many of us view the Z/28 as a performance vehicle with an awesome heritage (despite some of the later gens. missteps) and a new Z/28 should be that great performance vehicle again. Apparently some of the Chevy execs finally "saw the light" and decided to change the new vehicles name to ZL1 (which had it's own awesome heritage) and reserve the Z/28 nametag for an offering more true to the heritage of the original Z/28. And we still might see something other than a NA engine, but in a more appropriate vehicle, whether it be at the tail end of the fifth gen or in the sizth gen, or both.