I'm sure there will eventually be a happy medium where a page/app is rendered on the server, but upgraded asynchronously to be as dynamic as it needs to be, so we'll see the convergence of apps and pages. The return of progressive enhancement, I suppose - but even better because of pushState, indexeddb, etc.

That's if there's truly some benefit. Server-side rendering has its place, but probably isn't important for apps on the very "app" side of the content-app spectrum. What makes me want very easy to use server-side rendering, even for apps, is the fact that so many of those apps have embedded content - say an email in Gmail - that it'd be great to reuse the same templating if it's later deemed important to have a link to a static version of the content "outside" of the app.