I'm assuming this change will mean that it can use the video thumbnailers already installed rather than specifically needing ffmpegthumbs which would allow more control over the thumbnail generation if someone wanted to modify the relevant thumbnailer file without needing to patch ffmpegthumbs to make the change.

Having said that I wonder, for video files, if the ThumbSequenceCreator functionality will still work in dolphin and show a sequence of thumbnails on hover for videos if it's not using ffmpegthumbs.