Some people here seem to see SLI as something that will be a cost worthy upgrade for mini enthusiasts. I don't think the performance from a very good SLI setup with mid range cards can match the performance of the top of the line card alone. Let's say the top of the line card is 500$? and mid range 200-250$ x 2 + a more expensive mainboard for the dual SLI config. Or we can skip that and make it as plain as possible.
The performance of the SLI config wont double from that it had when running single card config. My guess is max around 75%? boost from SLI.
Isn't SLI more of a fun thing for the most richest that have the possibility to buy all the stuff?
Don't really think it's a solution for any other market.
And dang does BTX have any solution for SLI?
Imagine the heat and power requirements!