Hi Surry,
This is a preview. It is expected to be released end of February. This can change. For now you can only use a 90 day trial license. Please find announcements and some information about AX7 on Partnersource. Initially about 40 languages and 16 localizations will be supported. The first release will support new implementations only. I do think a re-implementation also might be a new one. You have to be aware of all requirements for AX7. If you have customers where you can start with an analysis phase, for sure you can start an implementation. But you cannot configure the production environment yet. Also note that it is now a pre-release. Functionality can still be changed.