A major goal of Google Chrome was to improve user enjoyment and value in web surfing. Critical to that is increasing the responsiveness of the browser to user input, or reducing user perceived latency. Measurements in the browser have shown that a significant amount of time is traditionally spent waiting for DNS to resolve domain names. To speed up browsing, Google Chrome resolves domain names before the user navigates, typically while the user is viewing a web page. This is done using your computer's normal DNS resolution mechanism; no connection to Google is used. As a result, user navigation time in Google Chrome when first visiting a domain is on average about 250ms faster than traditional browsing, and the occasional but painful 1-second-plus delays are almost never experienced.
I don't expect this to add much load to the DNS infrastructure and it should be a visible performance improvement for end users.