How often will this be a board-wipe, and how often will this be targeted removal?

Since the pronoun "You" designates both singular and plural, players can always be gramatically correct when they decry that "You are the weakest link."

Well... that is, assuming there are creatures in play.

Oh verrry nice. Blows away all the utility creatures AND the token swarm, whilst leaving your evil masterplan untouched.

Doesn't do you much good if your opponent is beating you with a big stick, but can't have everything.

As it's not targeted, does this technically get around prot-black?

Indeed, in the same way that Wrath of God gets around prot-white.

And yes, this is a great design. It's like a whole pot of honey all at once rather than a Drop of Honey each turn.