Recommended specs for highest settings & resolution with all MVPs and enhancements activated? I think any Core 2 series CPU and a GeForce 8600 series GPU are reasonable. Obviously MUCH older hardware can still run the game pretty well, but for near-perfect performance in WiH I'd say that's fair. Any good gaming computer since 2007 shouldn't have any issues IMO.
Strangely, I have a Core 2 Quad Q9400, GeForce GTX 295, and 6GB of RAM and Karunas still tend to give my computer a run for its money.