There is one argument in the filepath/tag debate I have hardly seen:
Yes, tags might be better and fulfil all needs that filepaths can do, but most tagging systems I know work only within the application you use.
Switch from f-spot to shotwell (or digikam), boom all information is lost. While if it's in the folder 2012/07/Boston/ I have at least some information to reconstruct where the picture was taken. This is why I don't want to give up file hierarchy based locations even if I like tagging.