Here is a script to crop all PDF pages to trim box that I made at work. Its Modified a version of the script found here:http://macproductionartist.wordpress.com/2009/04/01/really-cropping-pages-in-acrobat/
tell application "Adobe Acrobat Pro"
tell page 1
set tbox to trim box
end tell
tell active doc
tell every page
set media box to tbox
end tell
end tell
end tell