As of today, you can download some of the content on Steam using all-new server and client code to get the job done.

The new content system is designed to do two things: deliver better download rates in more places around the world, and also to simply streamline the publishing process on Steam, ultimately making it possible to ship more games than we would have been able to with the old system.

The maximum aggregate bandwidth of the system will be greater than the current system; this will help us satisfy spikes in demand when there’s a big release. We will also be able to send content from more places, to better serve people all around the globe. All the content on the new system is sent via HTTP; this is more firewall-friendly than the current system, and will automatically take advantage of web-caching proxies installed at ISPs.

Another way that the new content system improves the bandwidth picture is by requiring each user to download less data. With the Steam content system that’s been in place for a few years now, if an individual file on disk were modified by a game update, your client had to download the whole file. That can be painful when the file in question is really large. The new system supports delivering only the differences between the old and new files, meaning game updates will be much smaller overall.