Full Brutal Legend postmortem now available online 25 Mar, 2010 / Comments: 5
Although excerpts from it have been previously made available, the postmortem for Brütal Legend that appeared in the December issue of Game Developer magazine is now available in its entirety on Gamasutra. The comprehensive look back by executive producer Caroline Esmurdoc on what went right and wrong during the project's enormous production is more than worth the read you're going to be giving it.
oh well, like eltee said, very insightful and honest.. suits DoubleFine! :)
External playtesting, perhaps? It works for Valve.