http://www.battlefield.com/battlefield3/1/beta

It's finally here!

Also here are the system requirements

Recommended System Requirements
OS: WINDOWS 7 64-BIT
PROCESSOR: QUAD-CORE CPU
MEMORY: 4 GB
HARD DRIVE: 20 GB
GRAPHICS CARD: DIRECTX 11 COMPATIBLE WITH 1024 MB RAM (NVIDIA GEFORCE GTX 560 OR ATI RADEON 6950)
SOUND CARD: DIRECTX COMPATIBLE
KEYBOARD AND MOUSE
DVD ROM DRIVE

Some pretty heavy stuff.