Can't wait for this thread to be bumped in 4 or 5 years!
I don't know when the Switch will overtake the PS4, but I'm fairly certain it will happen at some point. I expect the PS4 sales to drop off a cliff by the time the PS5 releases. I could be wrong though.
Official member of VGC's Nintendo family, approved by the one and only RolStoppable. I feel honored.