In my previous comment "almost nothing is known about E_{11}", you may have wondered why the word "almost" appeared, and P.P. Cook has an answer.
Another small remark: on Friday Joe Marsano spoke about the symplectic structure on the phase space (space of solutions) of the half-BPS bubbling solutions asymptoting to AdS5 x S5. And it turned out he is an extraordinary speaker. Because the LLM machinery has already been described on this blog, I won't repeat Joe's excellent review of the basic picture. In calculating the symplectic 2-form - which can be written as an integral of something that can be called a symplectic current - they used the formalism of Witten and Crnkovic, among others.