From NATS point of view it obviously makes sense to have that pool of applicants to process as and when they're ready, as whitelighter said.
However, from an applicants point of view it's a bit of a pain with regards to lifestyle. For me it's the difference between buying a house and setting up a permanent base or renting somewhere I can leave and move to Hampshire for training with minimal fuss (and financial crippling).
Obviously I'm going to wait to hear from NATS before buying but it'd be very handy to know if the process would continue in a couple of months or in a years time (or over).
It's a great opportunity so it's a no brainer waiting but that's my main gripe.