Quick update: the much awaited Dota 2 game has been officially released for Linux (Steam). This isn't the "Dota 2 Test" but the real thing so you can play with regular Dota 2 users, as you can see in the screenshot below:
Like many other games, Dota 2 doesn't show up in the Linux section on Steam yet but you can add it to your Steam library and it should work.
As a reminder, the game is free to play and has the following minimal system requirements:
- OS: Ubuntu 12.04;
- Processor: Dual core from Intel or AMD at 2.8 GHz;
- Memory: 4 GB RAM;
- Graphics: nVidia GeForce 8600/9600GT, ATI/AMD Radeaon HD2600/3600 (Graphic Drivers: nVidia 310, AMD 12.11), OpenGL 2.1;
- Network: Broadband Internet connection;
- Hard Drive: 8 GB available space;
- Sound Card: OpenAL Compatible Sound Card.
Optimus users: for better performance, install Bumblebee, then right click Dota 2 in the Steam Library and select Properties, then on the general tab click "Set launch options" and use the following command: "optirun -b primus %command%" (without the quotes). With this, the game should use the Nvidia graphics card.
Below you can watch the official Dota 2 trailer:
(direct video link)