Whatever testing they are doing is revolving heavily around Product Search results for our niche. When the box is there it's shifting position, when it's gone image results take it's place. This is VERY worrying as it suggests a lot of our conversions came from the product search results box (as our conversions have been as erratic as the one box results). They are either going to make it a paid service (doubtful seeing as they do not police the prices people claim now, loads with incorrect prices & claims of free shipping which are not true) or they are going to drop it. My ££ is on dropping it, it MUST hurt Adwords performance (which is why they have also been testing Adwords in with the Product Search results!). Google has just become too greedy, adverts everywhere & constantly looking to minimise the SERP's. They are no longer a search engine, they are a data manipulator.