I will wait for more details and try to play the beta before crying too much... I can't see how VATS can be incorporated online and that is a big loss for me. I hate PvP, mainly because I am shit at it, so I hope there is a way to avoid fuckwits who just want to kill you.
Having thought about it some more, it should be ok - I enjoyed GTA Online (invite only or SP lobbies) before they forced you to mix with other players and I don't think Bethesda want to alienate the single player so I am more hopeful than a few hours ago...