Double Smite: What does it mean?

(Note: Doesn't seem to be an in-game change yet, just tool tip)

#EDIT:# it's gone :(, hopefully they're just holding it like Zz'Rot portal until next patch

If you scroll down to the bottom, you'll see there is a change that gives smite 2 charges. This is a pretty interesting way of helping out with early clears, but I think what's more interesting is it's mid-late game implications, as well as potential for laners to pick it up.

EDIT: According to JadeKnightBlazer, 15 second cooldown between uses; still awesome, but does a lot to curb the abuse cases :P

One thing I'm interested in finding out is; can you smite the same target, and does it stack? If so:

• Stalker's Blade just became a 2 second root (unless it's calculated differently; in which case, 75% slow is still massive) that also deals true damage comparable to ignite, on a much lower cooldown
• Skirmisher's got a heck of a lot more powerful
• Ranger's is unbelievable waveclear (even if you can't smite the same target)
• Poacher's still seems lackluster in comparison; though counterjungling is easier, you don't have to worry as much about saving your smite
• You can now double smite Teemo
• Objective contestions just became a lot more interesting (easier to smite steal since it's more likely you'll have at least one smite up, but the other jungler could double smite for tons of damage)
• Laners who have trouble farming early could benefit, not to mention supports can smite two targets with Stalker's blade and use it to proc Relic Shield early.

What else?