Primal had a 10 minute wait this evening, but it's also Tuesday so a lot of people are raiding. Other than the one ten minute queue the wait has been from instant to 4-5 minutes, from 5:30 EST - 9:00 EST.

Regardless of raids, I too am a little concerned that Feast has been out less than a week and queues are already showing signs of drying up. If they implement match making then it'll be game over.