Mac users who use Google Chrome today will receive a special treat. Chrome for Mac OS is now 64bit in the version 39 update which was pushed to the stable channel today.
Along with a whole bunch of security fixes and performance improvements, the new 64bit only version will allow for greater stability, performance and above all better security going forward.
Those who have been using the beta/alpha versions of Chrome have had 64bit support for sometime now and during testing it was reported most people saw noticeable improvements (especially when it came to video performance).