When you use the mp3 editor to change the cover art with the use image from choice have the browse button default to the directory were the mp3 is located. This would save a few steps for those users that have their covers in the mp3 directory but use some other name scheme than cover.jpg, folder.jpg or even GIF, BMP files. Also would be helpful for the correcting of incorrect art for an album in a few clicks.

In the "File info" part, you can "DoubleClick to go file". Then you just need to drag the right cover in the editor.