It has been stated before and it's a good thing, the website won't include any JavaScript. It's the current "cool thing todo" and makes all the Ruby-MongoDB-JavaScript-Whatever-Hippsters happy, but in many/most cases, it's really not needed.
The URLs are friendly enough as well. Yes they have some .php at the end, is the world gonna end because of it? Nope. Are the search engines having a hard time understanding it? Nope. Are the users confused on which site they are? Nope. Do people looking at the URL not understand where they are being linked to? Nope.
So much drama for a bit visual advancement.
Whether or not the website will be made open source is Laurent's decision and if he decides against it, then he can handle the back-end however he wants. Of course I'm sure he's always open for constructive feedback, that can be adjusted quickly (i.e. no whole rewrite of the website, etc...)!