I have my 'Uploads' set to the default uploads folder with 'Organize my uploads into month- and year-based folders' checked. I just updated some old posts (2006-2007) that had the image files located in another part of my server to the uploads folder in WordPress via the Edit-Add Image/Media. To my delight, instead of putting the pics in a folder dated 2012>01 as I would have thought it would do, it put the images in a folder of the appropriate date ie. 2006>06 etc. Just wanted to say thanks to whoever figured that out!