i just checked the CS3 features, apparently it's supported:

http://www.adobe.com/products/aftereffects/features/

i'll do some more research on this.
do you know if flv export is supported in the render queue in CS3?

i'm looking for the same thing. i have made this script which i believe should work. but it breaks due to the flv settings window. is there a way to get past this? var aComps = new Array(); var n = app.project.numItems; for(i=1;i<n;i++){ var myItem = app.project.item(i); // find all compositions if(...