If you edit and save a lot of photos, you'll notice the file output size is missing from the "Preview" app in OS X Lion. You can still select the image quality when exporting by moving the slider from Least to Best, but the output size that's normally below that has been taken out. I've fiddled around in the preferences pane, but can't find any options for this particular feature. One way to see the file size in an image you're working with is going to Tools > Show Inspector, but that's not convenient unless you've already saved the image. Any ideas how to bring this feature back, or any alternatives?