One is even a burst-1 power.
A burst-1 enemies only Dex vs reflex power, at that, and one that provides a sweet, sweet shift 2.
Given the nature of the monk's extra damage feature, I'd expect -every- optimized monk to take Five Storms (except monks that were built primarily to do maximum damage against solos, which might take Dancing Cobra instead, as it does d10+dex+wis+wis+2 on the first hit in a turn, which is rather nice--but if you care more about average single target damage, you're still better off with Five Storms, which lets you do wis+2 flurry damage to your primary target when you miss the primary and hit your secondary).
<Looks over monk options>
Hmm. Has anyone tried a monk Polearm Momentum build? Needing the 13 Str to multiclass to fighter is annoying, but the stat requirements are trivial, monks can easily make sure every attack they make uses a spear (or take a feat to learn a polearm), and monks have a -lot- of slides and pushes in their repetoire (aside from flurry, which isn't an Implement attack, of course). One hundred leaves becomes a blast 3 enemies only damage+slide2+prone, Strike the Avalanche knocks your target prone as well as everyone you slam them into (and then you use the movement technique from StE to walk over the lot of them without drawing opportunity attacks to get to the crunchy back row), etc. You'd need Rushing Cleats (and a controlling weapon, if you go polearm), of course, to make a bunch of other Monk attacks slide 2s, and you'd be gimped on attacks until PH3 comes out as monks stop getting slide/push attacks after 7th level right now, but it looks interesting.