The original Shuriken Toss never made sense. Why would rogues, a purely melee class, want a single ranged attack? We don't have the supporting toolbox to make the transition into a ranged DPS spec. Melee uptime is our top priority. Because of our reliance on our melee attacks, mobility is our most requested feature. Why would a class want Shuriken Toss when they can have Shadowstep?
Patch 5.2 is turning a one-off ranged ability into everything a rogue needs to attack targets from range. If you use Shuriken Toss on a target that is farther than 10 yards away, your auto-attacks gain a 30-yard range for 10 seconds. The auto-attacks turn into tiny shuriken that you throw at your target. These shuriken have several special properties, but the extended range is obviously the most important aspect of the ability. With Shuriken Toss, ranged auto-attacks, and Deadly Throw, rogues suddenly have a ranged repertoire.