As noted by our sister-site WMExperts.com, Palm has dropped the price on the unlocked GSM Treo Pro to $399 - formerly $549.
In the United States, this Treo Pro will work on both AT&T and T-Mobile, though it will only be able to handle 3G data on AT&T. Unfortunately, AT&T never picked up the Treo Pro as a subsidized handset, but at $399 that may be less of an issue for some. They have certified it as a "Speciality Vertical Device", which essentially means that AT&T recognizes that the Treo Pro is fully compatible with their network.
There hasn't been much speculation of late about the Treo line (all the action has been about the Pre and the Eos), so it doesn't appear that this price cut is some sort of stock-clearing effort to make way for new Treos.