Chrome version 40 for desktops and Android/iOS is out now available for update. There's nothing major in this release even though the version number has hit 40. There's plenty of bugs that have been eliminated as well as a new updated page info and contents setting UI. Other than that, it's pretty much a minor update. The update should be rolling out in stages for the mobile platforms.
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January 22, 2015
Well this move by Microsoft isn't so bad- it's actually quite smart. They want you back using their system and they are willing to throw in free upgrades just to entice you to use their latest and greatest operating system. No more complaints of "can't afford an upgrade" anymore, and even then, Microsoft is apparently bringing in a brand new web browser (heck, noone liked Internet Explorer).
The operating system will be released later this year. Right now if you are extremely keen, you can grab a copy of the Technical Preview (but you shouldn't use it for a production system).