Google has announced that it will begin rolling out video previews for searches done in the Google App and in Chrome, but only on Android for now. The video previews are accessed the same way as the old thumbnails, with the only difference being that they move. These video previews will not produce any sound, so you won't have to worry about a quick search for a video possibly singling you out in a crowd. The rollout will begin today on Chrome and the Google App, both only on Android, and should reach all users within the next few weeks. Google did not say when or if support was planned for other platforms.
The new feature manifests as simply as imaginable; just scroll over to a video result in the ticker, and it will begin to play silently. Tap on it, and you will be taken to that result. Scrolling to another result will stop the one that's currently playing, and start up the new one. It should be noted that video previews are enabled only on Wi-Fi by default, most likely because even with Google's compression algorithms, a made-to-order video preview likely still takes more data to deliver than a comparable GIF image. Going into the settings for either the Google App or Chrome will allow you to enable the new feature on mobile connections, or simply disable it entirely.
Google has been making a lot of efforts to improve its search tools lately, creating a more cohesive and natural experience. If you are searching for a video, after all, it should logically follow that you would have a better idea if a result is the video you're looking for, or contains the information that you're looking for, if you're able to see part of the video in motion, rather than a single moment of the video frozen in time as a thumbnail. Other recent efforts to improve the Search experience include adding local events, and even putting in a job searching tool. This all comes in the wake of improvements to the results themselves as Google cracks down on misleading, offensive, or low-quality results.