If you didn't know, Adobe Flash was previously sand boxed on Windows, ChromeOS and on Linux. Mac OS was the only OS left over, and a sand boxed Flash solution was on it's way.
Google announced yesterday that the Flash plugin on Chrome for Mac uses a new plugin architecture, which is said to be just as strong as Chrome's native sand box and more robust then anything else available.
You should be able to grab the update by now on your mac. I'm not sure how Chrome updates on a Mac because I've never used one -- or a store demo ~4-5 years ago doesn't count.