The seductive advantage of server side rendering is centralized control of what all clients see. Whenever you push too much business logic down to the clients you have to contend with how to ensure all of those clients are using the same logic at all times.
This is just a result of loose architecture. If your models are cleanly abstracted using REST principles on the server-side, then server templating becomes much more appealing.
I say this because I am doing it -- building apps with REST interfaces on the server side. It's not a common pattern yet but I think this is where things will actually go (as opposed to the client), because it's actually easier to use, understand and iterate on.
If you can write Javascript templates that interface with your back-end using REST calls like "GET /accounts", you can do the exact same thing in a server side template with better performance and dramatically simpler security.
Exactly. Correspondingly, my hope (along with one of the folks below) is that advances in hardware will obliterate any speed difference and enable the back end to be king.
