There are so many ways of comparing the two phone. It comes down to a few factors for me.
-As far as the OS, The Droid 2 comes with Froyo but the Droid X will have it soon enough. The launchers are mostly identical.
-Screen Size. I've held both phones and like screen size of the Droid X over the Droid 2. After using 4.3 inches for a few weeks, the 3.7 onscreen keyboard feels cramped.
-Keyboard. The Droid 2 has a improved keyboard. The keys are raised a bit more this go round. The physical keyboard also makes the cramped onscreen keyboard point a wash. With the Droid X however, you have plenty of space for that onscreen keyboard.
-Form Factor: The Droid X feel slimmer even though the camera hump makes it almost as thick as the Droid 2 at one end. Still I prefer the Droid X in the hand, but I have big hands.
Battery: Now I haven't used the Droid 2 to measure the differences in battery life. I know with the Droid X, I usually get 1.5 Days with medium use. I also want to mention that the Droid X seems suitable for a battery upgrade because of the camera hump. The usual manufacturers will be kicking them out soon I'm sure.
I don't really see myself using the HDMI or the DLNA too much. The 8MP camera is nice and takes great pictures in my opinion.