The official minimum requirements have been released on the warhammer website, so this isn't some NDA breaking information lol.
PC SYSTEM REQUIREMENTS
For Windows XP
· 2.5 GHz P4 processor or equivalent
· 1 Gigabyte RAM
· A 128 MB Video Card, with support for Pixel Shader 2.0
· At least 15 GB of hard drive space
For Windows VISTA
· 2.5 GHz P4 processor or equivalent
· 2 Gigabyte RAM
· A 128 MB Video Card, with support for Pixel Shader 2.0
· At least 15 GB of hard drive space
Supported Video Cards
ATI Radeon(TM) series
· 9500, 9600, 9800
· X300, X600, X700, X800, X850
· X1300, X1600, X1800, X1900, X1950
· 2400, 2600, 2900,
· 3650, 3850, 3870
· 4850, 4870
NVIDIA GeForce series
· FX 5900, FX 5950
· 6600, 6800,
· 7600, 7800, 7900, 7950
· 8400, 8500, 8600, 8800
· 9400, 9500, 9600, 9800
· GTX 260, GTX 280
Intel(R) Extreme Graphics
· GMA X4500
Laptop versions of these chipsets may work, but may run comparatively slowly. Standalone cards that are installed in vanilla PCI slots (not PCIe or PCIx or AGP), such as some GeForce FX variants, will perform poorly. Integrated chipsets such as the ATI Xpress and the NVIDIA TurboCache variants will have low settings selected, but should run satisfactorily.
Please note that attempting to play the game using video hardware that isn’t listed above may result in reduced performance, graphical issues or cause the game to not run at all.
The NVIDIA GeForce FX series is unsupported under Vista.
Source
EA Mythic | Warhammer Herald