"Keeping him in the lineup more"? The man has been a machine, appearing in 155+ games in all but two of his full seasons. Last year was 156, 2005 was 160. Playing time has never really been an issue for him.
While I disagree that his BA will improve very much over the past few years, his power numbers should definitely be there. He's especially valuable in leagues where OF position matters, as there are only 3 other guys who can provide numbers on the same level (Wells, Beltran, Sizemore).
Also, I wouldn't be concerned about a trade. Andruw is a 10/5 guy, and he probably won't want to leave Atlanta until the end of the season. He'd probably have to have a deal in place to agree to the trade (and even then, I doubt Boras would let him sign without testing the market), and the Braves would have to be out of the race by the trade deadline (which I would be surprised to see).