1. Ability to sort contacts by last name, first name. My old Droid 1 gained this ability with Froyo. It sucks not having it due to Blur.
2. I wish hitting the voicemail icon in the lower left corner of the dialer would dial my VM + automatically input the password. Instead, I have to push and hold "1" on the dialer or select it from the alert screen. Not a biggie but yet another shortcoming of the Blur "tweaks".
3. Improve the non-Gmail email app. It's a bit better than the stock Android email client but only barely.
4. Fullscreen mode in the stock browser (like Dolphin HD has).
5. More reliable camera operation. I still occasionally get black screens when launching the camera app, when taking a picture, or when switching between still & video modes.
6. As stated above, work on the horrible lag. After this week's update, the lock screen lag is mostly gone but I still get lots of lag after performing various tweaks and cache clearings. Another biggie is the "black screen lag" when powering the screen on and waiting for the unlock swipe screen to appear. That's a huge annoyance.
7. Wi-fi, 3G reception, and battery life improvements are always welcome (and needed).
8. I'd like to see Moto release a lower-priced desk dock that omits the HDMI-out feature and just charges it (like the Droid 1/2 dock). It also needs to be redesigned so the DX can be docked and removed more "loosely" & easily with one hand.