These are the minimum system requirements. I couldn't find others
Minimum System Requirements for Starcraft 2
Processor: 1.4 Ghz Processor
Memory: 512 MB RAM
Graphics card: 128 MB RAM video card capable of Hardware TnL. DX10 is not required, but will be supported by SC2 and Blizzard are considering adding DX10 specific effects.
Pixel Shader 2.0 (Officially Confirmed)
Soundcard: A DirectX-compatible 16-bit sound card.
OS: Windows Wista, Windows XP or Mac OS. (Officially Confirmed)
Connection: Access to Blizzard Entertainment's online gaming service, Battle.net, requires a low-latency, active Internet connection rated at 28.8 Kbps or faster.
Multiplayer games played over a LAN require an active connection to a TCP/IP network.
Other: Mouse and Keyboard