[JoshTriplett]

I don't actually think an entirely client-side-rendered application makes sense; on the contrary, I do think it makes sense to do most HTML generation on the server, and where appropriate, hand out snippets via the API, rather than handing out JSON or similar and making JavaScript produce HTML. But that's different than rendering entire HTML pages entirely on the server. And for primarily dynamic content, I see nothing wrong (for many sites, at least) with assembling server-provided HTML snippets from JavaScript into a server-provided HTML base page, without any fallback to an entirely server-provided page.