As a user, I want to edit the page title and slug in the site editor (which currently isn't possible)
THESE ARE NOT FINALIZED DESIGNS

Currently on hold and awaiting further discussion @dubielzyk @shaunandrews
I believe the most important part right now is just moving the page/post title up into the top bar, and have a drop down with the permalink available. That seems to be the MVP at present time. At the same time we also need a page/post title block.
Getting this in a soon as possible would help us see how it functions with having the page/post title in the middle of the top bar. As one would be able to gain a lot of feedback from this.
@paaljoachim yep, we're working on the page/post title bits of this right now. We're waiting a few days for some more design iterations on the dropdown aspect of things, since the early design prototypes generated a lot of feedback and discussion. Jeremy has a PR open (#25386) which starts exploring the dropdown approach if you want to check it out
I posted design updates GIFs over in https://github.com/WordPress/gutenberg/issues/20877#issuecomment-698466981

If the label isn't clickable, I don't see why we wouldn't make the whole thing a button to increase click area. Like where this is heading
I don't see why we wouldn't make the whole thing a button to increase click area
It addresses the accessibility feedback that if the text is going to be a button, it should describe the action the button will do. (this comment explains why).
Though I do totally agree that the text being a button would be very helpful for one set of users, it seems that it would be a hindrance for another.
We will not be making page name and page slug editable in the site editor for now. We can return to this whenever "template editing" is better developed.
I vote to leave the issue open for now, just on hold :)
(From my understanding...)
This looks like a good way forward.
I do feel there is agreement of adding the permalink and the title to the drop down.
I would suggest going with @shaunandrews suggestion but leaving out the template part. That can be added in the next iteration.
Most helpful comment
I posted design updates GIFs over in https://github.com/WordPress/gutenberg/issues/20877#issuecomment-698466981