Google Shopping has recently announced that it will be updating the feeds specifications, which is a part of the new Google Shopping rollout that is based on the product listing ads. The changes will have an effect on the accounts globally.
The most impacted will be Google Shopping accounts that are at present excused from using unique product identifiers. The Google product identifiers often show results for collectibles, vintage items, and custom goods. These accounts will no longer be using unique product identifiers, instead they will use "identifier exists" attribute.
Google's recommendation of using high resolution product photographs will be another change that will have a positive impact on the shoppers. The minimum accepted resolution for these photographs is 800×800 px. Shoppers love to see high resolution pictures that can be further enlarged (zoom-in) to get a detailed view. Although, the change is only a recommendation so merchants with sub-optimal image don't have to rush for high-quality pictures. Although, better images will certainly result in an increased revenue.
The last change is for sellers who offer a mix of non-family safe items on their family safe websites. They can now tag the non-family safe items individually.
Google is not making all the changes available at one but it wants to give enough time to merchants to adapt themselves to the changes before officially releasing them.
The change will take place on July 15 in the U.S. and September 16, globally. The enforcement for other accounts in the U.S., UK, France, and Germany will start on July 15 and on September 16, globally.
Here’s the complete list of Product Feeds Specification: http://support.google.com/merchants/bin/answer.py?hl=en&answer=188494#USGoogle Announces Changes in the Shopping Feed Specifications!,