Google is apparently quite proud of their six week release schedule for Chrome. They've taken to their blog to post about how every six weeks, Chrome gets faster. They liken the release schedule and speed increase to " a mechanic stopping by every six weeks to give your car a new engine."
As you can see in the chart above, Chrome, according to Google, has gotten 26.3 percent faster since version 15. The latest version, 24, is currently available in the Beta channel meaning it will be a little bit before you get it on your normal desktop. They measured performance using their Octane benchmark, so the numbers could be a bit biased.
They do bring up the interesting point of most users not realizing their browser is being upgraded. To the end user, they see the same window, day after day, even though it's updating the back-end to make the browser run quicker and feel snappier. Google strives for speed, so you can be assured that they will continue to tweak Chrome to get the best performance.