it's down yoy for december, but for november and december, sales are flat. the months were distributed a little differently between this year and last. in 2012, november ended on the 24th. this year it ended on the 30th. in 2012, december ended on the 30th. in 2013, it ended on january 5 2014. so december had one less holiday-crazy week this year than it did last year.
november 2012: 540k
december 2012: 1.25m
total: 1.79m
november 2013: 770k
december 2013: 1.1m
total: 1.87m
i think the wii u's jump during december indicates whatever they sold in november must have been on black friday. actually having advertisements on television probably helped boost sales too. last year, the vita was flat from november to december. i expected the same for the wii u this year.