Just to back up what mixmastermike has said,
I found stage 3 the most stress free part of the recruitment process. If you have done the work and prepared well then there is no reason why you won't get through.
Learn the motivation papers, visit some ATSU's and have answers prepared for the HR questions like "Tell me about a time when you were heavily scrutinised? How did you deal with it? Would you deal with it differently if it happened to you now? etc etc
Best of luck guys, maybe see some of you at the college soon!
Kev
Oh, and I never got asked to identify any aircraft in my stage 3 interview, although that was a year ago, its possibly changed!