There will always be PPS sieving. Think about it this way:
Originally we sieved n=0-3M. I don't know if that started as manual sieving, but before I came here it was on BOINC. While that was on BOINC, at some point manual sieving was started for n=3M-6M.
When it seemed that 0-3M had been sieved far enough, sieving on 0-3M was suspended, 3M-6M moved to BOINC, and manual sieving started on 6M-9M. That's where we are right now.
What will happen next is that sieving on 3M-6M will be retired, 6M-9M will move to BOINC and 9M-12M will start on manual sieving.
I create new sieve files about once a month. At that time Lennart and I discuss whether it's time to change over yet. So far we've decided the time hasn't yet come.