For the past couple weeks, I've been running around with a Shadowstep build.  I was very cautious about ever returning to this type of rogue build based on my past experiences from a long time ago.

For PvP (with decent gear), IT ROCKS!
The recent buffs to this talent tree are significant and make it probably "the" premier FOTM rogue PvP-style build -- replacing the nerfed HARP build.
[HARP = Hemo, Adrenaline Rush, Preparation]

I thought I would never be able to give up mace stun procs from Mace Specialization, but the burst damage and utility talents up to Shadowstep makes up for it.  With 1450 AP and a 30%+ crit rate in PvP GEAR (not raid gear), my Hemos are hitting like a truck and crit constantly.

Cheat Death is scary good too.

Current Rogue Talents: Shadowstep Build (non-daggers)
http://www.wowhead.com/?talent=fhe0oxZZxMe0MGRsxst

Assassination (17 points)
    3/3 Improved Eviscerate
    5/5 Malice
    3/3 Ruthlessness
    1/1 Relentless Strikes
    5/5 Lethality

Subtlety (44 points)
    5/5 Master of Deception
    2/2 Dirty Tricks
    5/5 Camouflage
    3/3 Initiative
    2/2 Elusiveness
    3/3 Serrated Blades
    2/2 Heightened Senses
    1/1 Preparation
    2/2 Dirty Deeds
    1/1 Hemorrhage
    3/3 Master of Subtlety
    5/5 Deadliness
    1/1 Premeditation
    3/3 Cheat Death
    5/5 Sinister Calling
    1/1 Shadowstep

DW Combat Shadowstep
http://www.wowhead.com/?talent=fZhfV0bVZxMe0MGRoxst

Combat (20 points)
 3/3 Improved Gouge
 2/5 Lightning Reflexes
 3/3 Improved Slice and Dice
 5/5 Precision
 2/2 Improved Sprint
 5/5 Dual Wield Specialization

Subtlety (41 points)
 5/5 Master of Deception
 2/2 Dirty Tricks
 5/5 Camouflage
 3/3 Initiative
 2/2 Elusiveness
 3/3 Serrated Blades
 2/2 Heightened Senses
 1/1 Preparation
 2/2 Dirty Deeds
 1/1 Hemorrhage
 5/5 Deadliness
 1/1 Premeditation
 3/3 Cheat Death
 5/5 Sinister Calling
 1/1 Shadowstep

Why Sinister Strike is a more damaging Combo Point generator for fast weapons than Hemorrhage.

Many patches ago, Blizz came up with the concept of “Normalized Damage."  I seem to recall it made itemization more diverse or something like that.  One of the problems they had was some super slow weapons that were blue quality were sometimes more powerful than faster purple/epic weapons (i.e. 2.0 spd Barman Shanker from Blackrock Depths).

Anyway, Sinister Strike is a rogue attack that uses Normalized Damage.  Hemorrhage was not “normalized.”  So they have slightly different damage mechanics.

The Old Non-Normalized Formula – Still applies to Hemo and Ghostly Strike

Damage = base_weapon_damage + (weapon_speed * Attack Power / 14)

For Attacks that are “Normalized”

Dagger Base Multiplier = 1.7 regardless of speed

Swords, Maces and Fists = 2.4 regardless of speed

The Normalized Formula:

Normalized Damage = Base Weapon Damage + (Base Multiplier × Attack Power / 14)

Here is an example.

Merciless Gladiator Shanker (Main Hand Season 2 Dagger)

140-211 Damage, 97.5 DPS, 1.8 Speed.  AVG HIT = 176

Assume 1300 Attack Power

Hemorrage: 176 + (1.8 x 1300 / 14) = 343 damage.  Hemo is 110% x 343 = 377 Total

Sinister Strike: 176 + (1.7 x 1300 / 14) = 334 damage.  SS is 98 + 334 = 432 Total

1.8 speed is about the slowest dagger you will have in Outlands.  Illidan drops a 1.9 speed dagger.  That’s it for lvl 70 endgame daggers slower than 1.8 speed J.

The faster the dagger, the more Sinister Strike outpaces Hemorrhage.  Sinister Strikes fixed damage bonus of +98 also outpaces Hemorrhage’s 110% modifier on fast weapons due to their lower damage range.

Maces and Swords just get better and better for Hemorrhage.  Many are slower than 2.4 (their normalized speed modifier).  So there is a good itemization supply in the game.