12. A system for differential dynamic content delivery, the system comprising: a computer processing unit configured to provide a session document for a presentation, wherein the session document includes a session grammar and a session structured document, the session document further including a first classified structural element and a second classified structural element received from a presenter; computer memory configured to store a session copy of a first user profile including a first user classification associated with a first classified structural element; the computer memory further being configured to store a session copy of a second user profile including a second user classification associated with the first classified structural element; a user interface configured to receive, from the presenter, a user classification instruction to change the second user classification in the session copy of the second user profile; the user interface being configured to change the second user classification to an altered user classification in the session copy of the second user profile to associate the second user classification with a second classified structural element in dependence upon the presenter's instruction, wherein the first user classification remains associated with the first classified structural element; means for presenting the second classified structural element to the second user in response to the second user classification becoming associated with the second classified structural element; and means for presenting the first classified structural element to the first user in response to the first user classification remaining associated with the first classified structural element.
12. A system for differential dynamic content delivery, the system comprising: a computer processing unit configured to provide a session document for a presentation, wherein the session document includes a session grammar and a session structured document, the session document further including a first classified structural element and a second classified structural element received from a presenter; computer memory configured to store a session copy of a first user profile including a first user classification associated with a first classified structural element; the computer memory further being configured to store a session copy of a second user profile including a second user classification associated with the first classified structural element; a user interface configured to receive, from the presenter, a user classification instruction to change the second user classification in the session copy of the second user profile; the user interface being configured to change the second user classification to an altered user classification in the session copy of the second user profile to associate the second user classification with a second classified structural element in dependence upon the presenter's instruction, wherein the first user classification remains associated with the first classified structural element; means for presenting the second classified structural element to the second user in response to the second user classification becoming associated with the second classified structural element; and means for presenting the first classified structural element to the first user in response to the first user classification remaining associated with the first classified structural element. 22. The system of claim 12 wherein said first user and said second user are registered participants scheduled to receive the presentation, and wherein said presenter alters the second user classification in the session copy of the second user profile.