Presently the mechanics for pvp do not permit rogues the same finesse and functionality that dungeons do as many players have well over 150% fortification by the time they head into the pits. Many other classes also rely on backstab for damage but for Rogues this is their bread and butter. Any changes to PVP at all i would personally put on the Low Priority or Extremely Low Priority list right next to new colors for Reaper cloaks or something else equally cosmetic due to the relevancy of PVP to the game generally. Even so, trying to backstab a 350%+ fortification warlock many years ago (a very specific one on Argonnessen, you might know what its name is...) resulted in absolutely no backstabs no matter what i did (shiv did not help, bluff did not help, and that level 6 assassin core did not help - i forgot its name). This is why a while back i asked for the rogue assassin level 6 core to gain fortification removal per level (and per epic level) so that my little knife swinger could participate in the big boy fun time. I do not know if you did anything with the Sneak Dice bypassing fortification as i have had a lot going on in life.