Post at official forums (not blue) -
The main name of the game here is strength gems- due to a hidden buff, Strength gives 1.3 AP where 1 agi would give 1 when factoring attack power in your special damage on the Ambush ability. Ever notice why warrior crits hurt so much more even while you're wearing resilience gear? New research has conclusively demonstrated that str reduces the effects of resilience although it doesn't independently alter critrate and crit bonus when not in the presence of resilience, such as in PvE.Due to a notation error, none of this is reflected in the character sheet's AP, but that's because the Character Sheet is notoriously sloppy with displaying values anyway.
A suspicious tester has confirmed using 2-4 damage white vendor weapons that there's a great deal of 'hidden' AP being supplied through strength, just as there are with windfury procs, and we later confirmed this also applied to Ambush as well. This revelation was also brought about when people questioned why Warriors hit so hard on high resilience players.
This is why Strength was so wide-spread on Rogue gear before Burning Crusade, but it's been systematically eliminated from the current gear setup- this is why certain items, such as the PVP Feral Druid bracers actually are better defensively AND offensively for a rogue. You won't find this information on WoWWiki, Blizzard has repeatedly reverted that Wiki page as others attempt to bring it up. This makes it widely unknown to the general populace of the Rogue class- while Warriors have Blissfully continued getting 2k+ crits with crafted weapons, unaware but benefitting off of the unknown component that not only increases attack power but -also- damage range.
So the benefits of a strength stacking Shadowstep Ambush rogue are doubled- you get the benefit of the increased attack power normalization on the Ambush ability, coupled with the effects of eluding the crit damage bonus reduction of resilience- you can see the strength of this spec, enchant, and gemming setup already.
Another -
Basically, what this means is that the new backstab formula - when the hidden AP and resilience mitigating effects are calculated in can be found as so:
[1+ ([(2*1.02*1.75 -1)*1.24 + Str*1.8/42 +1]*[1 - (Resil/3940)*2] -1)*(Target's Resil + Agi*Str/10557.5 + base critrate - 450/3940)]*([([BaseSTR * (STR*1.1) + 69*1.1]/14)*2.4 + 280.5]*1.2 + 42)*1.02*.18 = New ShS Backstab Formula
Remember this also applies on white attacks, shiv, ambush, etc. This will cause us to entirely re-evaluate str as a viable stat, particularly for crit oriented specs.
