According to the info here;
Call of Duty, World at War It's going to be using the same engine they used for COD4 and the sys' req' for that is..
Recommended requirements:
CPU: 2.4 GHz Dual Core or better
RAM: 1GB for XP and 2GB for Vista
HD: 8GB Free Space
GFX: 3.0 Shader Support, Nvidia Geforce 7800, ATI Radeon X1800 or better.
Minimum requirements:
CPU: Intel® Pentium® 4 2.4 GHz, AMD® Athlon™ 64 2800+ processor
or any 1.8Ghz Dual Core Processor or better.
RAM: 512MB RAM (768MB for Windows Vista)
HD: 8GB Free SPace
GFX: NVIDIA® Geforce™ 6600, ATI® Radeon® 9800Pro or better