This one happened this morning, and started gradually coming up for users. Some of the iSmashPhone staff got the updated Google before others.
It seems that it's making its way around, and should probably be in full swing by later this evening. The above screenshot shows an example of the new feature. It streams search results in real-time. This is an interesting idea, and it reminds us of a similar idea that Apple recently filed a patent for "Immediate Search Feedback."