Today Drysc post the upcoming changes for rogue class regarding pvp arena mobility:
"
Q u o t e:
Yeah Drysc, what is it? Tell us!
Do you mean the amazing change to Shadowstep so that it can now be used at any time, not only while stealthed? In addition, after use of Shadowstep threat caused by the next Ambush, Garrote or Backstab will be reduced by 50%. The cooldown will however be increased to 40seconds.
Also on the Subtlety front is a change to Dirty Deeds so that it will also be increasing damage of special attacks by 10/20% against targets that are below 35% health.
We're also taking a look at bumping up Hemorrhage a bit, but no details yet on what that may be."
Source
I really like the Dirty Deeds change, Shadowstep and threat relation is kind of weird imo...