Render the client on the server, then push the rendered markup and the client state to the browser where the client takes over again.
This paradigm is fundamentally different from the Angular1-style "render everything in the browser" and "maybe pre-render on the server, then discard that on page load" approach. If anything, it's closer to the traditional "render everything on the server, then apply enhancements in the browser" approach of the pre-SPA days.
Angular2 is following the exact same approach. Although the isomorphic bits aren't production ready yet.
Basically Angular2 renders a completely interactive view that captures any user events that occur while the app is bootstrapping in the background. Once the app is loaded, the events are replayed to make the user experience consistent.
React and Angular2 are fundamentally just different flavors of the same underlying infrastructure. React is more de-centralized and composition based. Angular2 is more centralized, monolithic, OOP, architecture based.
They have even eluded during presentations that the 2 core dev teams have been in direct contact to work out some technical details.
From what I've heard, Ember.js uses these same approaches. Kinda makes me question how much of this started with Ember and was later adoped by React and Angular.
Render the client on the server, then push the rendered markup and the client state to the browser where the client takes over again.
This paradigm is fundamentally different from the Angular1-style "render everything in the browser" and "maybe pre-render on the server, then discard that on page load" approach. If anything, it's closer to the traditional "render everything on the server, then apply enhancements in the browser" approach of the pre-SPA days.