The technology that allowed custom ROMs like CyanogenMod on the Droid X/2 and Atrix - 2nd-Init - has now been ported to the Droid X2 by XDA forum member edgan. According to the source thread, it was a direct port from the Atrix, as the code was not modified whatsoever, only re-compiled.
Before I go any further, let's get one important piece of information out of the way: this does not unlock the bootloader or allow custom kernels; it simply brings full custom ROM support.
This is still in very early stages of development, so it's recommended that the average Joe leave it be until devs can spend a little more time with it.
For more information, including download and full installation instructions, check out this thread at the XDA forums.