We know that a beta version of Chrome for Mac is due at least by the end of December, but today brings more confirmation that it may be even closer than that. Mike Pinkerton, the guy leading the Chrome for Mac team, has just tweeted out that there are only "8 remaining M4 Mac beta blockers! Go team!" This means that there are only 8 things standing in the way of Chome for Mac going beta. "M4" stands for "milestone 4," which is how they phrase "version 4," which the Mac beta build of Chrome will be (the current dev channel version is 4.0.249.12, for example).