Sometimes the devs do things and I just don't really understand why.
In this case, I kind of do. They wanted to buff deadly throw, and it's not exactly clear as to how. The damage can't go up that much, and the lockout power, while not considered greater than the other options on live, is still something that could become WAY too good if overtuned (there was that one video from BC of a rogue stopping all non instants from a shaman for like two minutes straight, and 1 CP deadly throw was a big part of that).
But this buff is definitely odd. It means that deadly throw will become pve and pvp utility more than it already is. Already deadly throw had some use in raiding because of this buff (though it would really hurt the dps).
So is it the right buff? Maybe. Either way, I'm definitely excited about it. Deadly Throw is one of my favorite moves, and I still remember the player thread that spawned the move in the first place. It seems that DT will, for the first time since the MoP made it a talent, actually be worth a talent point in more than just extremely niche situations.