Man! for me that would be a very hard choice. I mean the X's screen is absolutely amazing, but the D2 is the real deal with the physical keyboard. To me, that's what it all boils down to - keyboard/screen. Good luck. I don't think you can go wrong with either.
Welcome! Hard choice. I'm sticking with my Droid. I like the ability to switch roms, OC, theme, etc. It has been a very stable phone and meets all of my needs. The new Pro is scheduled to be released so I may feel different after.