DailyTech noticed some NVIDIA PDF files have quite a few references to a GeForce 4500 X2 adaptor:
On Thursday, NVIDIA released six new Quadro FX adaptors, including the Quadro FX 5500 series which is exactly the same as a Quadro FX 4500 but with 1GB of GDDR2 memory instead of 512MB of GDDR3. However, the Quadro FX 4500 X2 has not been announced yet, even though it shows up all over NVIDIA documentation.
NVIDIA insiders tell us the Quadro FX 4500 X2 is two Quadro FX 4500 adaptors built on the same PCB used for Quad SLI GeForce 7xxx series graphic cards. The Quadro FX 4500, which already consumes 108W during peak operation, can usually be had for approximately $2,000. NVIDIA insiders tell us the X2 uses more than 200W during peak operation, but would not reveal core or memory clock speeds. The behemoth features four Dual-Link DVI outputs, and is SLI-ready for Quad SLI.