Any "SLI on a single card" product doesn't require an SLI capable motherboard (9800GX2, GTX295)
Only running two separate GPU boards which communicate from different PCIE slots requires an SLI motherboard.
In fact they don't even call it SLI in the control panel with the dual gpu boards, they call it "multi-gpu", since SLI is specifically reserved for the case of two separate boards.
I doubt the 295GTX would saturate the 1.1 PCIe bus. Easy enough to find out by just comparing some 3dmark scores of 2.0 vs. 1.1 motherboards with this card once they start showing up on futuremark.