I know i've been away for a while, and probably don't have time to really get involved again. But it's hard to resist a GUI discussion, and maybe i can help move this along.
Some Preliminary Questions:
* Has the idea of having a party been abandoned? None of these GUIs support multiple characters. A good GUI for a party is very different from a single player game GUI. Even if you don't directly control them, you'll want to know some of your companion(s) stats and status
there was something bugging me the whole time I was thinking about the layouts and what should be visible at all times. And now I remembered - the party members or temporary followers...
* I found the little text box crammed into the side of fallout's hud inadequate and annoying. And if Zenbits has his way our calculations won't be nearly that simple. We need more room for it. I'd put that text readout in it's own box that can be resized, and it can be turned off when not wanted.
here I have to disagree, Fallout happens to be one of the only games where that text box never bothered me. I found that the messages added a lot to my gaming experience, I liked to examine
everything, partly to get to know the world and partly to see what the developers didn't feel like working on

the resizing and hiding remark I with absolutely. I keep forgetting that the GUI does not have to be just static pop-up windows
* Temperature bar should probably look like an actual thermometer, i.e. not a red-blue gradient, but a red line (or silver) that stops at the level temperature.
but of course
* Character and Inventory screens should be separate, unless there is some compelling reason they need to be visible at once. I think there will be too much info to fit at once anyway.
Why I put them together was because there are some statistics that the persons equipment changes one way or another, some resistances, be they location specific or not, encumbrance, some items may add to skills (a good set of lockpicks makes picking locks tons easier that just a hairpin) etc. So if that information should be available to the player one way or another then why not show the two screens together.
I get your point though I personally wouldn't be against scrolling if everything does not fit in one window.
But that depends on how much information there is going to be, information that's going to be displayed that is.
[quote author=eleazzaar
* I don't see a need for a window navigation between "trade, loot, sell, steal, gamble". These actions will be rarely available from the same object, i.e. if you click on a box or a corpse, you can only loot. "Trade" and "Sell" should probably be the same interface, i don't see a reason to distinguish them. This and especially gamble could be accessed via dialog. "Steal" is should probably be an action you initiate against a person.
[/quote]
yes, well, that wasn't intended as navigation. I put all the 'commands' or 'choices' together just to show that the window they will go with is the same.
So when you use your Pickpocket skill on someone this window pops up and you can select an item (or items) and then press 'steal'. Same with Looting and when you trade, again, you select the items you wish for, a running count of the price will be presented to the player in the/a feedback window and when they're ready they press Purchase or Barter. While you're selecting the NPCs items you can also select your own and their prices will be compared to the NPCs.
and the compass I didn't really include anywhere this time over because I really didn't know how it could be used in the game.
At first too, the GUI mockup I have at the Wiki, the compass was intended just as a skin, the display would display health or 'action points' or whatever