The problem as I see it is that there is never a right time to do it because with the length of time it takes from deciding it's what you want to the point of applying for your first pilot job takes so long that the industry can have swung completely in the opposite direction.
Put it this way, if you wait for it to be a great time(like now), it'll be two years before you get a job (minimum), if you do start now and there is a downturn you may go though several hard years, but look at those who stuck it out in the early nineties when times were really hard, they were the first ones to be taken on when the industry turned round and are now in, if not, pushing for command. Those qualifying right now are joining an industry which has recruited quite heavily for the last few years and therefore (like myself) are now faced with having a lot of 'junior' pilots in front of them in the seniority list. Not trying to say it's all doom and gloom, just that if you are convinced this is where your future lies and have the determination to never give up you do not need to worry. You will get a job, but it will also be very hard work.
Good luck
PP