I suspect some international standards dictate how the copyright and production information are worded.  And for that reason there are a few years where the To Go Cup ornaments are identical except for French included on the bottom for the USA/Canada ornaments.  And then for the new logo design, the TM/MC and TM differences as noted in another post.  Look over the below infographic to see the variations between the 2009-2012 USA/Canada and Japan ornaments.

Update: Since this was originally posted I discovered that 2008 was also a year with a variation. Here is a quick summary of the red cups release by year and region:

• 2004 One version
• 2005 One Version
• 2006 USA and Japan have unique versions
• 2007 USA and Japan have unique versions
• 2008 USA and Japan have same version with bottom stamp variation
• 2009 USA and Japan have same version with bottom stamp variation
• 2010 USA and Japan have same version with bottom stamp variation
• 2011  USA and Japan have same version with bottom stamp variation
• 2012 USA and Japan have same version with bottom stamp variation
• 2013 USA and Japan have unique versions
• 2014 USA and Asia and Europe have unique versions
• 2015 USA and Asia have unique versions