Yes, illustrator offers a really nice “reflect” tool. But I prefer using command + Shift H or command + Shift V and don’t care much for the “paste in place” I replace, as I’m happy with paste in front and -back.

tell application "Adobe Illustrator"
if (count page items in document 1) > 0 then
set selectedItems to selection
set scaleMatrix to get scale matrix horizontal scale 100.0 vertical scale -100.0
transform every item in selectedItems using scaleMatrix
end if
end tell

I’m using them with the wonderful Fastscripts, by red sweater, since it takes a very sane approach to scoping (limiting to intended application) the installed scripts.

Grab the scripts HERE