I'm in the same boat as some others here it seems! Getting time off work at such short notice won't be easy... That's if it is positive news of course! I guess BA have covered their own backs by getting us to sign that document/form saying that we would be available in the respective weeks for Stage 2 and Stage 3.
It's a shame there isn't more time in the process really - given the start dates for the course aren't until September this year... Maybe that's just me being critical though! From what others have said, we could be getting as little as 2 working days notice!