If you look at NPD end user sales though, PS4 is no longer selling like hotcakes. The trend will push it below Wii and PS2 rates after a historic start soon enough.
Remember PS2 and the Wii came out at 299$ and 249$ respectively. PS4 and XBO are beating that at higher price (33% higher to be exact ).
And let us not forget... First year of PS2 [after NA launch] had truly phenomenal software lineup: Twisted Metal Black, GT3: A-Spec, Final Fantasy X, Silent Hill 2, Ico, Devil May Cry, Metal Gear Solid 2, Tony Hawk's Pro Skater 3, Jax and Daxter and Grand Theft Auto III. That was one of the best years of gaming of all time. All those games were exclusive to PS2, all [except Ico, who became cult hit later on] were welcomed in a highly positive light.
And in 2002... 95% of game releases that are listed on Wiki are PS2 exclusives, and 7 out of 10 most successful games of the year were on PS2.
http://en.wikipedia.org/wiki/2002_in_video_gaming
All this means... that we dont need to think that PS4 can sustain the monthly sales of cheap PS2 and cheap Wii [which had incredible causal gamer appeal] over the long period of time... PS4 will never reach such hardware and software sale dominance. We should compare it to PS3/X360 reports, and not to the successes of highly dominant consoles like PS2 and Wii.