According to a comment by Ian Fettec, Product Manager for Google Chrome, they are not planing to release Google Gears for Apple’s Snow Leopard/Safari. The reason for this is the fact, that developers should make use of HTML 5’s new features, that prior where only available in Gears.
To bad because many sites are already using Gears (Google Docs, Gmail, RememberTheMilk, Zoho and more).
We are not supporting gears on Snow Leopard and later versions of Mac OS X.
Relying on HTML5 database and appcache going forward is a good approach as a
replacement for Gears on these platforms.
(Source)
So what do we do if we want to use offline docs on snow leopard?
Well, HTML5 contains offline application functionality (http://www.w3.org/TR/offline-webapps/). And this is the direction Google will go and hopes others will join.