Intel and Microsoft exposed the real difference in Managed Copy between the two formats, which was that initially on Blu-ray the studios could choose whether or not each title was copyable, so in other words it wasn't mandatory. The BDA eventually caved and as we've said before, Managed Copy on Blu-ray is mandatory. Another related note is that Managed Copy was never implemented on HD DVD either, as it was also dependent on the finalization of AACS, but what was different was that the Discs did contain data that pointed to what was expected to become authentication servers. So in theory, if the format would've survived, even the initial Discs would've been copyable when it was implemented. Of course we'll never get to find out if it would've worked, but at least they did plan ahead a little, which is more than you can say for Blu-ray.