Kalypso announces the system requirements for Tropico 4, their upcoming dictator simulation sequel. The minimum and recommend system requirements follow.

Minimum Required:
Operating System: Windows XP SP3 (32-bit), Vista / 7 (32 or 64-bit)
Processor: 2 GHz Dual Core CPU
Memory: 1 GB RAM
HDD: 5 GB free hard disk space
Graphics: Shader Model 3.0 (Geforce 6600 or higher, Radeon X1600-Series), 256 MB, DirectX 9.0c

Recommended:
Operating System: Windows Vista / 7 (32 or 64-bit)
Processor: 2 GHz Quad Core CPU
Memory: 2 GB RAM
HDD: 5 GB free hard disk space
Graphics: Shader Model 3.0 (Geforce 8800 or higher, Radeon HD4000-Series or higher), 512 MB, DirectX 9.0c