n00b1 - 5:56 pm on Sep 28, 2012 (gmt 0)
Well this is very interesting. I posed a question to John Mueller about this via the Webmaster Central office-hours, September 28, 2012 (b) hangout. He addresses the question 16 minutes in and basically says that Google does equate them as one domain. Returning a 410 on the affected version can work 'to some extent' but isn't as clean as starting on a new domain. He specifically said that algorithmically it is treated as one website!