BTW the blue buttons on top of the bars would have the same function as in BG - if you click on them the bars would collapse. So people could play with only the right bar, or without any bars at all, only utilizing the floating combat UI+combat log if they wanted to.
I really wish Obsidian would change their minds and make a BG-esque UI, since I have a feeling it would be really hard, if not impossible to mod in.
edit: The combat log+action bar in the middle is a must for me, I really can't stand the current UI.