The Jetson Nano module is available now for people designing a product, along with collateral necessary to create form-factor and use-case specific carrier boards. (See this forum post for a handy index of module collateral.)
Jetson ecosystem partners are already introducing new off the shelf carrier boards compatible with the production module. The following partners plan availability later this month:
Also, the current Jetson Nano Developer Kit is useful to get a start on software for a new product while hardware is being designed and trialed in parallel. We will refresh the devkit
later this year with new revision carrier board that supports the production module.