While PMI regularly adds, modifies and deletes individual questions in their overall exam "pool" for the PMP and their other credentials, there wouldn't be any significant changes just yet as they have not conducted a Role Delineation Study which is the prerequisite to updating the Exam Content Outline.
As far as the PMBOK Guide goes, there is a project getting underway to come up with the Eighth Edition but that won't have a direct bearing on the PMP exam as the PMBOK Guide is just one of multiple references for the questions on that exam.
