The newly released Motorola Droid X appears set for an upgrade to Android 2.2 in "early September." The information comes via a Motorola employee on the Motorola support forums:
Some Droid X users are experiencing an issue using Exchange 2003 email. Though the email is arriving on the Droid X, no notifications are appearing. A fix for this will be included in the upgrade to Android 2.2 scheduled for deployment by early September.