PK Tool Kit allows you to see what other players are wearing when  they come into range of your mini-map.  So now you know who is the twinked out newbie ripe for the picking. You'll also know prior to dueling what to expect.

Is it cheating?  I don't think so.  In real life you would know if someone was wearing Silks of the Victor just by looking at him, right?  Also, once an item is identified in the game, it never needs to be identified again, even if you give it to another player.  Therefore, even in the game, you know all the attributes items have just by looking at them.

Is this a hack?  I don't think so.  I do not manipulate the game or packets in any way. I just help you make sense of the data that B.net is sending to your computer.  Not sure why Blizz didn't make this available in the first place.

Will Blizz prevent this from working in the future?  They  need to send this data so you can properly render other characters on your screen.  Considering the reasons previously stated, I doubt they will think it is necessary to prevent my program from  working.