I think what saltlover's saying is that if they trade Batum they're effectively getting rid of Aldridge, since the two complement each other very well.
Yes, that and that trading a player who helps you win now for future draft picks is a great way to alienate your superstar player in the prime of his career who's on his first real contender ever. Essentially the logic is this:
A) Trading Batum will almost certainly cause Aldridge to leave in free agency.
B) Therefore most of the cost of Batum will be to compensate the Blazers for the loss of Aldridge.
C) If you're going to pay the Blazers for losing Aldridge, you might as well get Aldridge.
Note: I do not think the Blazers are going to trade Batum or Aldridge. I just think if you're a Celticsblog poster interested in paying the Blazers umpteen draft picks for Batum, it makes more sense to think about giving up those draft picks for Aldridge.