As was discussed and explained in another thread earlier this week: A specific firmware version created for one device will not work on an entirely different device. They may both be technically running the same operating system, be the same type of phone, on the same carrier or general subscriber, etc., but they are unfortunately
not interchangeable like that. It just doesn't work that way. You can potentially take things like media or application files from an already unpackaged firmware, and place it into another, but you can't swap entire software.
Froyo still isn't publicly released for the Droid X yet, (obviously) so there's nothing for us to, "push," to the phone that it will accept. This is stressed even further by the fact that the bootloader is still locked down and encrypted, so we have even less control.
However, AllDroid recently acquired what appears to be a dev Droid X, which has Froyo on it and a potentially exploitable bootloader. You can read more about the situation here:
http://androidforums.com/all-things-root-droid-x/145199-droid-x-developer-phone.html
here:
AllDroid (AllDroid) on Twitter
and here:
AllDroid Public Board - AllDroid Public Board - AllDroid.org > Home
If there's anything incorrect or misplaced in this post, please correct me. I whipped this post up somewhat quickly so I might have forgotten to go over something or accidentally stated something untrue. Afaik everything is correct, but I'm not perfect.