Yes, the PS3 is about to catch up to the XB1 in weekly sales!
It happens often that the XB1 is below 50k a week, there are even weeks where it's around 35k... those who think this is a sure shot that it will over sell the Wii U over its lifetime are overly optimistic, there are real chances if it never reaching second position (however I would not bet the other way around either).