Yeah data we have so far this year suggest WiiU might have a chance to be nicely up when compare to 2014. Something will be needed to match the MK8 boost though (like a price cut as you mentionned).

Yeah, the MK8 boost will be tough to top, but the Wii U has a more consistent library and the various games won't have to do as much heavy lifting as MK8.  Last year was largely spent rebuilding the Wii U and Nintendo's reputation I feel.  Now there's more general positivity in the media and around the net.  I still think a price cut will happen in March probably, near the end of the fiscal year; they're maintaining the current pricepoint to try and maximize their profits for their fiscal year. 

Update 21-02-15 :

No big changes WOW. WiiU down 15% overall due to Japan mainly (Xeno bundle appeared last week and was very high...). XBO up 10 % thanks to Halo MCC bundle in Japan.

Update 28-02-15

3DS trending down from last week (launch effect slowing down...). PS4 and XBO trending up from last week thanks to Japan and USA respectively. WiiU and Vita more or less flat WOW.

XBO took back the third spot in front of WiiU. But XBO still down YOY and WiiU still up.

Update 07-03-15

Nintendo in a much better situation than last year... 3DS steadily going down after New 3DS launch though...

Sony down YOY but PS4 still very high.

seems new 3ds is doing well except in the US

Well, the thing is that Amazon US is not selling the New 3DS XL at the normal price... (215$ for the black one and 230$ for the red)

Update 14-03-15

Interesting thread. Great work.

Update 22-03-15 :