One other area where abstraction is appropriate is form generation. I've used Django a lot and recently Clojure+Noir a bit, and in both of those I've ended up using an abstraction for all the form code (Django forms in the former, Hiccup+helpers in the latter). In the Clojure project I was even working with someone knew HTML and not Clojure, so most of the site is rendered using Mustache templates, but I ended up rewriting all the forms in Hiccup because it's just easier to work with.

All that said, you seem like someone that might like Enlive (https://github.com/cgrand/enlive). I'm not sure if equivalents exist in other languages, but the gist of using it for templating is that you write a plain HTML file, and run the text through Enlive along with some transforms (identified by CSS-style selectors). I've never used it for anything major, but other people have, and it seems really cool.

For example NodeJs allows to use same JavaScript for both client and server and if we will have smth like http://lispyscript.com/docs/#templates we can also seamless export business logic into templates (without need to create special template tags, filters, syntax, etc).

Single language for almost everything can be big performance boost IMO.