Nowhere have I seen this mentioned! When browsing through files in 7.2 builds, the Navigator shows a thumbnail image of image files:
Not only that but, as you can see, you also see the dimensions of the image. No need to open image files in the IDE again. Just move through the explorer views (Projects, Files, or Favorites) and, when you get to an image, the Navigator will show a thumbnail view of it. Very cool.