Google Operation System Blog wrote:

Chrome 12, the upcoming version of Google’s browser which is likely to be released today, removes a useful feature: the built-in Gears plugin. While most Google services dropped support for Gears and removed offline access, Gears is still being used in Gmail. Google no longer maintains Gears, which is now legacy software, and focuses on implementing offline support using HTML5.

Read the whole story in: Google Operation System Blog