There was a little scuttlebutt on "the other" bass boat message board about a month ago by one of the Nitro team members getting to see a Z-8 that was replacing the 901. After a few days the message was deleted by the poster. I guess he caught some heat for talking about it. Other than it was "pretty cool" that's all I know.
Being on the Pro Staff and the owner of a loaded 898DC these Z series have a long way to go to replace a boat like the 898 which I think is awsome. The front deck is huge and I'll fish one foot of water on trolling motor and go full speed across about the same depth of water. The hull is incredible.
A buddy of mine had an 882 with the same motor I have. The 882 is about 2 feet shorter and my 898 runs faster than his 882 did.