Yes, it probably can, but as I remember it, the rotation is lossy, i.e. it makes the JPEG data worse than before the rotation. jpegtran was able to do lossless rotation, which is why I picked it. For thumbnails it would not matter but for rotating original files it's not nice to loose information/quality. As long as users can get hold of jpegtran I think it should be the default program used for rotation.

Sounds good, thanks for doing this!

/Mathias