In the late 80's and early 90's I was hooked on a system called X10. It was a series of modules that you plugged electrical appliances into and then the modules plugged into the outlets. The system let you turn the appliances off & on with a remote control. You could also dim lights and other fun stuff.
Now comes SmartThings which is like the system mentioned above on steroids. Imagine something like I've mentioned above paired with your wireless network, your phone, the internet, and The Cloud.
Sound interesting? To me it sounds like a geeks dream come true. Take a look at the project on Kickstarter and make *sure* you watch the video. You'll be as impressed as I am.