Magazines spill the supposed system requirements for StarCraft 2. Minimum requirements are said to be at least a 256 MB RAM graphics card, a Pentium 4 CPU and 1 GB RAM.
The Spanish magazine Micromania visited Blizzard and says to have received the system requirements from StarCraft 2. According to the magazine, the minimum requirements of the game will be a Pentium 4 CPU, 1 GB RAM, a GeForce 7/8 Series or Radeon 1000/2000 with 256 MB RAM.
Blizzard employees have stepped forward saying these are not the official requirements, but the specifications given to Micromania was most likely gotten spilled after talking to StarCraft 2 developers.

Minimum System RequirementsGraphics Card: GeForce 7/8 Series or Radeon 1000/2000 with 256 MB RAM CPU: Pentium 4 RAM: 1 GB Internet: ADSL 1 Mbit Recommended System Requirements:Graphics Card: GeForce 8000 or Radeon 2000 Series with 512 MB RAM CPU: Core 2 Duo or Athlon X2 RAM: 2 GB Internet: ADSL 3 Mbit Optimal System RequirementsGraphics Card: GeForce 9000's or Radeon 3000's series CPU: Core 2 Duo 3 GHz or Athlon X2 RAM: 2GB with DualChannel mode |
Links
myMYM.com - Source
starcraft2.4players.de - Second source