Seriously? Just wait dude. The Droid X is an ok phone. For the record, I swap phones like socks. A phone typically only spends 2-3 months with me before I sell it and get another. And out of the 6 phones I've had over the last 14 months, the Droid X wasn't anything special. If you just want to save a few bucks now, then by all means take the free phone.
But, if you want the latest and greatest, get the Bionic or Atrix. Many people will tell you that "the latest and greatest" is always replaced in a couple of months. While that may have been true in the 2H of 2010 with each new phone boasting the same processors with only 100-200MHz difference in clock speed and different UIs slapped on top, the difference in between the Droid X and the newer Bionic and Atrix are huge.
For starters -- dual-core. *HUGE* potential increase. With the newer dual-core processors comes new GPUs which will give you better graphics as the new games come along.
As I see it, there's really no reason for the X unless money is really an issue. If performance is even a small consideration, get one of the newer devices.
As for Verizon or AT&T -- it largely depends on coverage in your area. What good is a smartphone without a usable signal?