PS4 is not settling at 20K. It has some bigger new releases and in reaction sales are up. They will godown again in slower weeks.
I have doubts the direct has a big impact on sales, if anything the general direct should have done more.
I think the increase this week was due to the direct. Sure it could have been bigger but it wasn't. And for now the ps4 is settling around 20k. Hopefully when the next batch of releases are over Sony cut the price it's so long over due.
At this point in the ps3 life it was 25k. Ps4 is over 30k.