Holding down A is grab.
360 controller layout its now confirmed:
A-Activate/Take if clicked/Grab if held down (Item stays 'grabbed' until A is clicked again to release it.
B-Inventory
Y-Jump
X-Draw/Sheath Weapon
Left Bumper-Sprint
Right Bumper-Dragon Shout
Left/Right Trigger-Left/Right Attack with Weapon/Magic
Start-Pause
Back-Wait
Right anolog-Look around and click for 1st/3rd Person
Left anolog-Move around/Click to Sneak
D-Pad UP--Skills(in inventory)/Down-Map(in inventory)/Left-Spells(in inventory)/Right-Items/Weapons(in inventory)
D-Pad UP/Down (outside inventory) is scroll through Favorites
D-Pad Left/Right (outside inventory) is select Favorites to Left/Right Triggers