GM don't attack any more. Most guards still do however. Last I checked, you could be attacked, but as long as the Banker wasn't under attack (Not sure if AEs affect the combat status of bankers or not) you could bank. With the change of Bankers not attacking, they should be ok all the time, unless, and I'm not 100% sure on this, they hit with an AE. Also, I'm not sure if even when I tried this, if you could initiate a banking transaction while being attacked, but if attacked after starting one, it wouldn't close.
I'm thinking, since you can't start a banking transaction now, with the spell book open, but you can start one and open the spell book after starting it, that being under attack prior to starting a transaction will prevent you from doing so. Again, not 100% sure.
I am 100% sure about GMs not attacking though. I spent alot of time in Neriak testing it out. Pretty much nothing but Guards, Rats, and a few other things were attackable there, and none that you couldn't attack would attack you. Not like the old days, where if you accidentally hailed a GM not of your class twice, that didn't particularly like you, would kill ya.
EDIT: Yther's been KoS to Kelethin Rangers for years, and they never attack, other than the butterfly NPC if I sit or med; None of the merchants nor GMs. Now, I just leave the building before I mem spells or Camo first.
Yther Ore. Edited, Mar 30th 2012 5:36pm by Yther