Hybrid SLI has been an interesting technology to watch. Similar to functionality in certain laptops, Hybrid SLI promises to both bring the advantage of discrete graphics on the desktop along with the power-reduction in using integrated graphics. Supposedly, Nvidia will be demonstrating just how it works later this week, along with the "GeForce Boost" functionality that pairs discrete and integrated graphics together for a (slight) performance boost.
While this is not something aimed at the extreme enthusiast, it is a practical application of existing hardware that shouldn't be overlooked. Particularly for those who tend to leave their computers on 24 hours a day, letting the system idle with the primary GPU turned off would be fantastic. Hopefully we'll here more later this week.