I know I'm late with this, but I did some searching and didn't find this suggested anywhere;
For 07, the Destiny rating should be a factor in trades, and should then also not be hidden. In the NHL series, the Potential rating is a huge factor in making a trade. This trade:
Player A - 75 overall, 60 Potential
for
Player B - 71 overall, 90 Potential
would almost never happen. Teams don't want to give up players with the Potential to become great. This would also be helpful when you're making a playoff run; you could trade some players with high Destiny for some older, but more talented players to help immediately. It would also prevent you from trading all your old players for younger ones with equal overall but who will become loads better.
Sound good?