Pretty much the same as usual:
CPU: i5 2500k $220
CPU cooler: Cooler Master Hyper Evo or better $35
Mobo: Asrock Z68 Extreme 4 Gen 3 - SLI/Crossfire support is needed, so less might do $190
Mem: 2x4GB 1.5V CAS9 1600Mhz $55
GPU: 2xGTX580 ( or 2xGTX570 if you need to save some ) $450 each = $900 ( $320 for 570 = $640 )
DVD: DVD burner $20
HDD: Samsung Spinpoint F3 1TB ~$60
PSU: 950W+ good PSU (for GTX580 SLI) $200, 850W+ for GTX570 SLI ( $150 )
Case: ~$100 range for good airflow
~$900 for everything but graphics
~ $1800 for GTX580 SLI, $1500 for GTX580 SLI
Then add OS if needed and a 3d capable monitor.
OS: Windows 7 Home Premium 64-bit OEM: ~$100
Monitor: ~$400 for 3d monitor of sufficient size