'Bout time for a different thread. :)
A couple of comments on things in the UI gleaned from a weekend in the beta.
1. There is a really nice feature that is not enabled by default. esc->preferences->general options has a box to click to enable AE looting. If you killed 3 things that have loot in the same area, as soon as you click on one of them all the items from all the different bodies show up in one window. All the usual loot settings are there (e.g. autoloot) as well.
2. When you have the preferences screen open, the different settings for the ui are grouped in categories along the left. Sometimes you need to scroll down the window on the right to see everything in a category. What might not be obvious is that there are tabs at the bottom of the frame to switch between ui settings and key bindings. While the key bindings start out similar to WoW, they are not exactly the same, and you might find it easier for your fingers to remember if you change them. (They use this tab-at-the-bottom arrangement in a lot of places--inventory, character sheet, etc.) I recommend fiddling with things when you get your first character made.
3. If you have a Mac and dual boot, the one machine we tried it on had a very sensitive mouse. We had to go into the windows control panel to adjust pointer sensitivity down, as well as turn it down in game. If you have problems mouse steering, try adjusting both places. Do not try to master the drunken jedi movement style.
4. As the game occurs thousands of years before "long ago", there are certain aspects of modern UI design that have not been discovered yet. You cannot move the boxes on the screen, you cannot change the scale. You can change font size and color. You can add in extra action bars, and you will need them in your teens. Supposedly, some of these things are on their list to add, but "soon" is already trademarked by Blizzard.
5. If you have a character that changes stances (e.g., cover), the primary action bar changes just like it does in WoW. The problem is that by default they put all abilities on your action bar as you learn them, and put on the stance bar only those abilities you can use in that stance. So, things change position. You might want to spend a few moments removing the things from your primary bar that you can't use if you aren't in cover (or whatever) and adjusting to get the same action in the same place on the two bars.
6. Quest items have their own inventory space...yay. You find them by using the tab at the bottom of the inventory screen.
Perhaps Zyrena has some other comments to add?