Finally! I've been hearing about Tesla's expected venture into consumer batteries for a while. I could see myself picking one up for our not-yet-built house/cabin in a couple years.
Fun fact: the battery pack puts out 350-450 volts!
Powerwall | Tesla Motors
Currently you can build your own LiFePO4 pack successfully which probably could compete with these packs, but I'm sure the Powerwall has some fancy controller to keep it running the best that it can. That plus the 10 year standard + 10 year optional warranty makes it mighty appealing.