Apparently (over a year and a half later) Lasermax kept my email address because I just got an email announcement that they've released a Guide Rod Laser for the 4.5" XDm chambered in 9mm or .40S&W.
Here's the link...I'm just passing it along in case anyone else owns an XDm and might find it interesting...
http://www.lasermax.com/product.php?id=1557
MojoTexas
