I currently have a single BFG 8800 GT OC and I am seriously considering adding a second in SLI mode however with the 9 series rumoured to be out soon I was thinkin of selling the 8800GT and buyin a 9800 GX2 (or whatever they are gunna be called) however would a 700W power supply be sufficient to run the system?? PC is as follows

Intel Core 2 Quad Q6600 (95W edition)
XFX 780i SLI board
2GB Corsair XMS2 Ram
700W Thermaltake Toughpower PSU
Antec 900 Case with an extra 120mm Fan added to side panel
A single DVD-RW
A single 250 GB Samsung SATA HDD