The US version will see a few small changes. There seem to be a bit more chrome than the one sold in Europe and else where. Also new wheels and a revised lower bumper. The big news is the announcement from GM of an all electric version called the Spark EV. No info yet on range or anything else. All we know so far is that it will be sold in what they call "limited quantities in select and global markets". Starting in 2013.
The Spark is a really small car, so this should be quite a bit less expensive than a Leaf.