PS4 is at 77 million now (VGC numbers obviously). Sony planned to ship 78 million ending March 31. They did it.
The forecast is 79 million shipped by end of this fj. Shipping 2.5M in the last quarter.
If we go by vgc numbers, they already sold over 2.8M units this quarter, with two weeks remaining, so there will be some empty shelves at random places here and there by the end of this month.