The latest report of the Special Working Group on the Crime of Aggression of the Assembly of States Parties of the International Criminal Court is now available: http://www2.icc-cpi.int/iccdocs/asp_docs/ICC-ASP-7-SWGCA-2%20English.pdf.
Although not the last word on the subject, it represents a growing consensus on many of the outstanding issues concerning the definition of the crime, and authorisation to the Court to exercise jurisdiction over it. The big problem is still unresolved, however: will the permanent members of the Security Council accept this. They haven't even blinked, so far. Everyone hopes that the solution will come at, or perhaps even before, next year's review conference, to be held in Kampala, Uganda, probably in April, May or June. No matter how much progress is made on the technical issues, the big political question remains.