All next-generation Nvidia cards will support Hybrid SLI, but you have to be careful about this promise. The soon-to-come Geforce 9600 might not support Hybrid SLI while it is still based on the old G92 chip, and dropped down to 64 stream processors, but the next real chip should support it.
Currently, Nvidia wants to keep Hybrid SLI for low-end products, as this is where you can get some performance benefits from it. We remember that we had a good laugh when Nvidia told investors that it wanted to enable Hybrid SLI for high-end products, as you would be happy to see 0.5 percent performance increase in such a case.
Today, when Nvidia was almost ready to launch it changed its tactics and said that currently only 8400 and 8500 support Hybrid SLI, and that some chipsets in the future will also work with it.
We are sure that Nvidia can enable Hybrid SLI on its 8800 generation of cards, but it would simply be pointless and it doesn’t seem to be able to do it, at least not now. It might make sense in hybrid power, as it would be able to handle a power greedy card and show your 2D desktop with IGP core and save some power at the same time.