Blizzard has released the minimum and recommended system requirements for upcoming WOW expansion, Cataclysm releasing December 7, 2010. Also, checkout the cinematic intro if you are yet to see it.
Minimum WOW: Cataclysm System Requirements
Windows XP 32bit (SP3), Windows XP 64bit (SP2), Windows Vista 32bit (SP1), Windows Vista 64bit (SP1):
- Intel Pentium 4 1.3 GHz or AMD Athlon XP 1500
- 1GB or more of RAM
- NVIDIA® GeForce® FX or ATI Radeon™ 9500 video card or better
- DirectX-compatible sound card or motherboard sound capability
- 25 GB free hard drive space
- A keyboard and mouse are required. Input devices other than a mouse and keyboard are not supported
- You must have an active broadband Internet connection to play
Recommended WOW: Cataclysm System Requirements
Windows XP 32bit (SP3), Windows XP 64bit (SP2), Windows Vista 32bit (SP1), Windows Vista 64bit (SP1) Windows 7:
- Dual-core processor, such as the Intel Pentium D or AMD Athlon 64 X2
- 2 GB RAM (2 GB for Vista users)
- 3D graphics processor with Vertex and Pixel Shader capability with 256 MB NVIDIA® GeForce® 8600 or ATI Radeon™ 2600 or better
- DirectX-compatible sound card or motherboard sound capability
- Broadband Internet connection
- Multi-button mouse with scroll wheel recommended
via WOWInsider