Orchestrator is generally available and here’s an unofficial FAQ on how it will be priced.
How is it sold?
The product will be sold via a Service Cloud add-on license.
What’s the Freemium Allocation?
All PxE, Enterprise, Enterprise, and Unlimited Editions get 600 annual runs included (regardless of org size).
Pricing Before any Discounts?
It’s a consumption-based SKU which means you pay $1 per orchestration run, and it’s sold in yearly increments. Customers purchasing in volume can seek discounts, as is usual.
Is there a way to extend Orchestrator usage to non-Salesforce users in my org?
Yes. There’s a new ‘no-cost’ Limited User License in the works that is designed to be assigned to users who don’t already have a user license. This will allow them to log into Salesforce and participate in orchestrations. The license will have limitations on it, so it isn’t a substitute for a typical Salesforce license. Final details are still being worked out.