Snapcaster Mage is already banned in at least one format; they had to make one that's THAT MUCH better?
What format is Snapcaster banned in? I can't think of one.
ETA- when I look on the gatherer, they have him legal in all four formats he would be legal in. (Modern, Vintage, Legacy, and Commander)
Anyway, as for the card itself...so the most anti-blue card in this set is in blue.