If anyone wants to do it with Norwegian dialects, there's an awesome set of audio samples of the same text here: http://www.ling.hf.ntnu.no/nos/nos_kart.html

("I would be willing to guess that no speaker of these languages would be able to differentiate one from the other" – I highly doubt that. Dialects/languages differ more and more the closer they are to your own; I can tell if someone grew up a 15 minute drive away from me, but if the choice is between a place that is e.g. >3 hrs north vs >4hrs north I have a really hard time placing them.)