Spyderco normally has 20+ models "in the works" at any given time. Add "byrd" designs and the number is higher.
Working with different makers, plus our own plant. Designs, protos, testing, etc. change schedules when "glitches" develop (Common in a new design) all contribute to schedule adjustments.
If we offered one or two new models per year, it would be far easier.
It is difficult to impossible to accurately predict when each model will come to market.
We normally inform the customers when we know a model is coming off the line.
In the case of "afi" stuff, like ZDP, first, there is waiting for the foundry to make the steel and for the steel to arrive at the factory. Hitachi doesn't stock steels like ZDP-189, it is all custom made, often requiring 8 - 9 months for delivery.
The Caly3 in ZDP will more than likely be availabe early '07, Jan or Feb, but even that is a "guess".
sal