bioshock 2 has been removed from gwfl's services. its no longer required to log in and will no longer be associated in any form with it.
you simply need to aquire the CD key (assuming you didnt buy it directly through gfwl) and register it through steam like a retail game. this will also carry over all your dlc's. those who own it through steam simply need to wait for a patch to remove gfwl to finish downloading.
as for those who purchased it directly through gfwl (i pity you so) you are SoL and will eventually need to rebuy the game through steam
this is the last of the games in the bioshock trilogy (and the last game by irrational) to be taken off gfwl.