The base idle itself is very low, it's supposed to be (below 500rpm). Is your CEL on? If so, I'd lean towards the EACV not doing it's job. Pull the codes to confirm that there's one stored for the EACV otherwise just unplug it and, when the idle doesn't change, you know that's the issue.

With a MT car, it can usually keep from stalling even w/o the EACV (and even when set at the proper base idle), but with the AT it's churning the fluid in the torque converter and more likely to stall.
In the meantime, you could try putting it in neutral as you're slowing down to try and prevent it stalling, or you can left foot brake and give light throttle to keep it from stalling when you come to a stop - that's what I had to do w/ a '93 Grand Prix that wouldn't idle by itself, ever.