If you've been examining the recent pictures of this board that have been leaked, you'll know that it only includes one SLI connector. OCW (via The Inquirer) has pointed out that for this exact reason, Tri-SLI will not be supported. This contradicts earlier reports about the three-way SLI properly functioning on the 8800 GT and lower end boards. However, The Inquirer points out that Tri-SLI can be achieved over the PCI-E bus, but that's going to be a "slow and buggy solution"...

Bad news for those hoping to pick up one of the new G92-based 8800 GTS cards - despite the co-incidental revealing of 3-way SLI around the same date from the green team, the new board won't actually support it. We saw the first pictures of the reference boards at the tail end of last week, and now OCW has quite rightly pointed out that, without the dual slot connector, there will be no hot 3-way action for the GTS. Whilst Nvidia reckons that Tri-SLI can be achieved over the PCI-E bus, that's going to be a slow and buggy solution for the foreseeable future.

To date, the 8800 GTX and Ultra are the only boards that have confirmed support.