Aaron Bradley posted on Google+ that the product schema page has added that it can be used not just in the web results but also in Google image search results.
I checked the old and new page and he is indeed right. Google added language to specify that product schema markup can be used in image search now. Here is the new language:
Add markup to your product pages so Google can provide detailed product information in rich Search results - including Image Search. Users can see price, availability, and review ratings right on Search results.Using markup to enable rich product results lets you attract potential buyers while they are searching for items to buy on Google or images that include products you sell. Maintain the accuracy and freshness of your product information, so your customers find the relevant, current items they're looking for.
To show your product information in the rich image viewer: Include the name, image, price, and priceCurrency properties. Alternatively, instead of price and priceCurrency, you can include any four properties and exclude price.
You can actually bring them up on your mobile searches, in image search. Kenichi Suzuki spotted it and I can replicate. When you click on an image result, it can show product data. Here is a screen shot:
Forum discussion at Google+.
