Over the next several weeks and months, you’ll see us move quickly here. We’ll iterate on the preview frequently – delivering modern page editing experiences, enabling seamless access to data in other O365 workloads through the Microsoft Graph, streamlining the tools, and moving toward general availability. In the longer term, we’ll expand the framework beyond web parts to custom pages and portals, as well as document library customization. We will expand support of the SharePoint Framework beyond Developer tenancies to the full set of Office 365 tenancies later this year. We will also make the SharePoint Framework available for SharePoint 2016 on-premises releases, targeting 2017. Keep an eye on this blog and @OfficeDev for updates.
Read more about it here.