The latest Dota 2 main client update brings us two compendium rewards and a modified team MMR system. This new patch is sized 437.9 Mb.
Two stretch goals rewards have been delivered in the 437.9 Mb main client update. The first one is the favorite hero challenge, and added were in-game performance analysis tool to help players track or see their progress. The next one delivered is stretch goal reward # 11, a 1v1 matchmaking option. Though it is somewhat similar with the mid-only game mode, it has specific 1v1 rules which ends the game when a player dies twice or loses a tower.
The team matchmaking system has also been modified, and is now merged into ranked matchmaking. You can now have the option to select a team when you form a party of five to seven. Other MMR guidelines follow, such as level 13 requirement.
There were also several interface changes and bug fixes. For those who fancy playing with/against bots, you will also be seeing Bristleback as he was added.
Source: Dota 2 blog, Reddit