For clarification, my order of preference when it comes to DRM schemes, from 1 to 100:
1) No DRM. DRM doesn't work, never has.
20) Social DRM like Pottermore's or DriveThruRPG's watermarking. While annoying, at least it doesn't actively interfere with how I use my purchase.
80) Adobe DRM. Still lousy for all the usual reasons, but at least if a great device comes out and licenses it, my library can transfer with a minimum of fuss.
100) Single vendor DRM such as Amazon's.
Adobe DRM at least allows for other companies to compete with Kobo directly with library compatibility. Still not good, but it's better then the Amazon situation where no company can advertise "Read your Amazon library on this device!" without being Amazon.
Now as for Amazon and the Voyage: never heard of the Canadian patent issue before. The goodereader article was interesting, and I thank Michael for the link to the actual patent. Pity his conclusions were wrong.
Amazon started the patent process in 2010 and finished the preliminary steps in 2011. However, as shown
in this CIPO tutorial, you have to kick off the approval of your application by applying for examination. You have to do this within five years of filing. Amazon waited three years, four months and eleven days from the last step they completed, or, put another way, five years minus 20 days of their original filing. Yeah, the Canadian market is a *real* priority for Amazon.