For one Steam is bolstering the total amount of bandwidth available. This will help deliver more content at once during spikes, such as the recent Steam Summer Sale, which slowed servers considerably. The worldwide availability of content is also increasing, meaning faster downloads for those overseas and is less populated areas.
The second change ushers in a new method for delivering updates, which many users have been awaiting for a long time. The previous system that was in place required you to download an entire file if any of it was modified . Now this may not sound like a problem, but many games pack all their files in a format called a .GCF, a proprietary format used for steam. These files can be many gigabytes in size, meaning one tiny modification used to require the user to redownload the entire thing.
The new system being put in place will deliver “only the differences between the old and new files, meaning game updates will be much smaller overall.” This change is very important because it will not only help reduce strain on Steam’s servers because much less data needs to be delivered, but also will significantly speed up patching time for gamers, especially those with slow download speeds.
New tools are also available to developers that “simplify the process of both publishing and updating a game on Steam.” Which will allow for faster development and certification of new games and patches.
Steam is also prepping updates that will include many new features, such as “downloading scheduling, bandwidth throttling, and prioritizing which games get downloaded first.” Which gives gamers on strict ISP’s better control over their data usage. Also in the future you will be able to download updates in the background while playing the game, and apply them afterwards.
While most of these changes are on the back end of things, they will hopefully make downloading much more convenient. Speed should increase significantly due to faster servers and smaller files, which gets games to your computer much faster.
Right now only a small amount of content is using the new delivery system, with more being transitioned over time. Currently you can download any HD trailer using the new system here, so try it out and see if you notice any differences. In the tests I preformed my peak download speed increased an average of 45%.
Valve threw in one final statement, saying, “soon Dota 2 will be delivered using it.”