Verizon and Motorola have both been teasing that they were "on track for a summer launch of Android 2.2 for Droid X," and taking into account that tomorrow is the last day of summer, they would not be wrong in all their teasing.
Some of the features of the software update, besides Android 2.2, are improved visual voicemail, better Bluetooth connectivity, a refreshed mobile hotspot application, faster Exchange email access, smoother camera functionality, and the Android Kindle app. There are also a host of other visual changes to present Droid X users with a smoother and more uniform interface. There also seems to be fixes to prevent connection issues when switching data connections from WiFi to 3G and vice versa.
Verizon has already posted an update document, and you can check it out here
The update is expected to begin rolling out to Droid X owners tomorrow at 9 a.m. ET, 12 p.m. Pacific.