That doesn't make sense anymore.
The service is offered for anyone who doesn't know, as a means of directly downloading mods from the workshop, without having to go through steam, but all suggestions I have come across is that it no longer works, after steam made some changes to their workshop website structure.
Beyond that is of course the fact that this game does not yet have steam workshop support, and there is no need of this service.
Though I can understand your foresight, hopefully it all works out!

I doubt that site would be needed for long after the workshop release anyway. Someone will no doubt create some kind of extractor for the workshop's mod files. (If the game devs don't release that extractor themselves, like in Skyrim and Garry's Mod.)

I tried Steam mods- hated it. It`s a complete control register bs system that should really ring alarms bells with a lot of people. It`s sad that it doesn`t. It`s not conveninet, it`s not freedom. It`s a chain disguised to make you think you have something good, especially with its attempt to cash in on modding recently.

Anyway, i`m experienced enough with the old days of modding to know how to install Mods without Steam and always support sites (such as the Nexus) that allows it. I download the Mod to my desktop and installing manually- It`s actually very easy. Steam makes kids lazy as hell as well as addicted to it, thinking there is no other way.

There are other better, more sure ways than Steam.

That`s my soapbox done.