This is a brief survey of some recent results on infinitesimal symmetries of bundle gerbes and their relation to three Lie 2-algebras associated to manifolds equipped with a closed 3-form, such as 2-plectic manifolds: the Poisson Lie 2-algebra of local observables, the Lie 2-algebra of sections of an associated exact Courant algebroid, and the Atiyah Lie 2-algebra.