Etsy has been rolling out support for Google Product Search for sellers. In the past you had to upload your items yourself using the rss feed. However there is a slight problem with the new syndication, it will only upload items added, renewed, or edited after activating the service. This isn't all bad, it means that Etsy will be able to update by only uploading new items once things have started rolling but right now when most sellers have items that predate the change it's an annoyance.
Go to Great Panes blog has a great tip for mass editing of your products so they will all be uploaded.
Blog Handmade has a tutorial on how to filter visits from product search from regular google search results. Very useful to see how many visits you're getting from product search and compare it to other search engines.
Etsy Storque post on this feature.