Hi Matt
We are not planning to charge for the Workbench, and in fact you will find elements of it's functionality creeping into the system slowly over the next couple of months (starting with the Belcanto scripting support in the exisiting browser). It is now likely (we been doing a lot of brainstorming here in the last couple of weeks, largely driven by all your feedback here) that what was originally intended as one monster application will in fact become several smaller ones that can be turned on and off from EigenD, as the need for some of the functionality is likely to be sporadic and they will use up system resources. This particularly applies to the graphical plumber now in development, as it will be a fairly heavyweight application that many will not use that often. And experienced Belcanto users can do pretty much everything it will do without launching it, albeit at the price of having to maintain a complex mental model of the system - easy after a year or so, much harder for beginners.
As of now we have no idea about the pricing of new native instruments, we will let you know as soon as we do. There will be several more that will probably make it into the existing EigenD releases at no cost.
John