The burst does come with gear, so I would imagine the enha shammies will do pretty decent. The jump from honor to conquest gear is monumental in terms of damage output. + the consistant off heals seem to be pretty strong and from what I remember from playing some 3s and 2s on single toons, enha shammies are pretty durable.

For comparison: here's a few of my games, capping Boomkins in 2s. At around 655 ilvl (unscaled), so close to gear cap:

Before getting quite geared the games were a lot more painful and landing kills on geared people was a real struggle. Now it's getting pretty consistant results.