The 41-point talent for rogues in the subtlety tree, Cloak of Shadows, never really impressed me. However, while I can't see myself spending that many talent points for it, I can certainly see its uses, and I know I'll be using it frequently if the change in the Burning Crusade beta -- making it a trainable skill -- makes it to the live realms. And before you think it's too good to be true and start pointing out that Cloak of Shadows is still listed as the 41-point talent in the official talent calculator, you should know that Tseric seems to have confirmed the change -- or at least, in his posted response to the thread about the change, he doesn't deny it -- only talks about reasons for making trainable high level talents.
Of course, if the 41-point talent is trainable, that leaves the question of what the new talent might be -- and I believe the above screenshot is legitimate. The Shadowstep ability is getting too much discussion on the beta forums for it to have been a fabrication by a single person.