The pile of bugs seem to only affect my older characters…
From my observations, all of my characters created between Aug 2012 and Jun 2013 have been affected by the bugs that were rolled out today. My characters created after Feb 2014 are not affected, and seem to be working fine.
I’m not sure if this is merely a coincidence on my account, or if it is indeed a bug that only affects older characters.
I tried your idea, and it seems to be the same for me. I logged on to my oldest character, and many things were bugged. (Mail carriers, Achievements, ect) Then I logged on to one of my more recent characters ( a Level 80) and everything was back to normal.