Last generation, Wii was the best selling console and the most popular, this generation it is PS4. Up until now we have seen identical sales between the two, during their first year on the market. I believe it is 'okay' to use Wii's results to somehow predict this Holiday.
-----Wii 2007--------------------PS4 2014--------------------------------------
Nov 03: 296,372-----------Nov 01: 301,173 = 01.62 % (4,801)
Nov 10: 282,996-----------Nov 08: 477,401 = 68.70 % (194,405)
Nov 17: 469,651-----------Nov 15: 433,298 = 07.74 % (36,353)
Nov 24: 673,069-----------Nov 22: 570,445 = 15.25 % (102,624)
Dec 01: 699,757-----------Nov 29: 1,049,137 = 49.93 % (349,380)
Dec 08: 728,498-----------Dec 06: 752,485 = 03.29 % (23,987)
Dec 15: 686,612-----------Dec 13: 781,557 = 13.83 % (94,945)
Dec 22: 1,462,609---------Dec 20:
Dec 29: 737,820-----------Dec 27:
Jan 05: 386,299------------Jan 03:
7 Weeks: 3,827,955------7 Weeks: 4,365,496 = 14.04 % (537,541)
*Due to extensive adjustments, PS4 will most likely not reach 21 million. However, PS4 should be able to reach 20 million.