For general continuity between games the R and L button should be switched on PS3 controls (not sure how games normally play on 360 so I don't know if that is good there) meaning right/left attack/block should be R1/L1 not R2/L2 and R2 should be dragon shout and L2 sprint/grab (grab added per previous suggestions in the thread). L3 should be sneak, though I think that had been mentioned already, too.
There is one other function missing I believe they have mentioned and that is a quick select, the logical way to do that I think would be made the D-pad out side of the menu bring up one or two (depending on how they set it up) selections similar to the way it was in Oblivion and you would push right and R1 to select something for your right hand or L1 to put it in your left hand (hopefully that is understandable).
The way I understood it was if you are outside of the menu the D-Pad works as quick select like you said with up&down scrolling through things you have bookmarked.
Left on the D-pad would then assign the bookmarked spell/weapon to the Left Trigger and right on the D-Pad to the Right Trigger.
Inside the menu you have D-pad change to up as skills/down as map and left/right to spells and inventory respectively.
I assume A button would be used to bookmark spells and Weapons.
Left Thumb stick/Move when pressed would continue to serve as crouch/sneak.
I do believe Sprint (Left Bumper) will share with Grab as long as the player isn't moving.
As long as your holding an object with Left Bumper you can only walk/sneak but cant sprint with it.
I'm assuming you can still grab items straight from your inventory as well and upon exiting the menu your holding the object just like in Oblivion.
I'm curious to see the menus and button layouts for when your cooking/chopping wood/blacksmithing etc...