My school just went from immediate to deferred rush this year. With immediate rush, quota was usually around 30-32. This year, it was 22.
If you look at the percentages, it's even bleaker, as the number of admitted women has been going up.
I think this is due in part to the fact that for the first semester of freshman year, you are graded pass/no record. (C or better = pass, D or F = no record that you ever took the course.) I think people are a little wary of balancing new member activities with classwork, other activities, jobs, etc, particularly during their first semester on grades.
Interestingly enough, fraternity rush is still in the fall, though it was deferred from August to September.
I'm not there, so I don't really have a sense as to whether this year's new members are more or less satisfied with where they ended up...