a lot of people left yeah, but hopefully some will return after the patch (looking at the thread about whos not playing and waiting, thats a fair amount of people).
The good thing is you only need 5 other people in the same time zone as you, to have a nice game. Last few days, I've had no problem finding those 5 after 18:00 hours
EDIT:
8 man game within 5 min waiting
. (the amount of people playing lately seems more than it used to be imho
)