The company are attempting to interview around 180 by the end of the year. Working on average success rates in the interview process, they are hoping that will yield around 100 odd new pilots.
It doesn't mean they will get them but it's what they are aiming at, knowing full well the string of resignations will continue throughout the year and well into next if QF keep putting people on.
As far as the VARA pilots progressing onto the 737, the company are requiring that they be interviewed and assessed in the sim before allowing them their GDOJ number to afford them a place on the jet. Given all of Qantas's subsidiary pilots are required to do the entire process as well, it's not an unusual request.
Understandably this takes time, and any VARA pilot delayed movement to the 737 will not find themselves junior to any direct hires should the later begin before them.
As Goat Whisperer has previously mentioned, there will be a huge requirement for 737 drivers over the next couple of years, so provided they meet the company standard they will move across at some stage.