It's certainly higher than it used to be, but I doubt many users would tolerate anything that high. I just did a quick scroll through my feed (first in a while) and it was pretty much what I expected to see. From comments I'm reading in this thread I can only assume FB have been doing some sort of A/B testing. Luckily for me I seem to be in the control group. Maybe because I only check my feed once a week or so...