Just to update you all as to the status, here is what I have done so far:
-Hard Reset (factory reset) of the Droid X
-Had Exchange Admin delete all ActiveSync relationships for my mailbox.
-Set phone back up for Corporate Sync with my Exchange account (and I verified that we are in fact using 2007 SP2.)
At that point, I again was able to get emails and Contacts on the phone, but my Calendar was once again only showing a few appointments from my Exchange Calendar. (Mostly, it seemed to be reoccuring appointments such as Birthdays and Anniversaries that appeared on my phone, the rest were missing.)
Since that point, I contacted Motorola Support. They asked me similar questions and/or suggested I wipe the phone and clear the phone relationship on the Exchange server. One thing they did have me do was add a new Driod "policy" on the Exchange server that is supposed to help with this. When I hung up with them (about 20 minutes ago), they told me to reset everything now that I have a new policy and wait a few hours to see if the items show up.
I also called Verizon, but was told that 1) They don't have the proper support documentation as the Droid X is not officially out yet and 2) Based on similar phones that they do support currently, they cannot go beyond checking that the Corporate Sync settings are correct on the phone. (Basically, they are saying that they can ensure the phone is provisioned and setup properly, but they cannot do tech support on the Exchange Server side.)
I kept my Exchange Admin abreast of this all, and he is looking for solutions from Microsoft to see if this is a known issue and/or looking through the Sync logs on the Exchange server.
I will again update you if anything comes of this situation.