For me, it would be bards. I just could never wrap my head around what the bard was actually doing in game.
Distracting attention from the Storm Sorcerers, of course.
("Don't look at the Storm Sorcerer with his single-target At-Wills, look at ME instead!")
Gah. During the year 2011, in the real world, Hurricane Irene was (at one time) in both Virginia and Vermont at the same time. What, 300 miles apart? So Storm Sorcerers have an At-Will attack power that covers:
Target: One creature.
Dang. "Blazing Starfall" is Area burst 1 in 10; but it has a Cosmic Magic rider to it. And "Burning Spray" is Close blast 3; but it has a Dragon Magic rider to it.
The Sorcerer At-Wills that suggest Storms are Lightning Strike and Storm Walk, each of which is Ranged 10, One creature.
Sure, we don't expect Storm Sorcerers to invoke Hurricane Irene at will; but aren't most storms big instead of precise?
That's why the Bard has to distract people from looking at Storm Sorcerers: they can see the shortcomings of Bards easily enough; and while they worry about that, they'll leave Sorcery alone. (Sort of.)