What's new in TOGAF 9.1?

TOGAF version 9.1 was released in the beginning of December. In this version, there are some changes which are clarifications, consistency and some additional details in some chapter where needed. Here you can find the some changes I found it important:

• The Document Categorization Model has been removed
• The usage  of the terms application versus system have been reviewed and made consistent.
• The objectives sections of the ADM phases have been reworked and remove  techniques and list of steps to emphasize actual objectives.
• The artifacts which can be used in each ADM phases were added at the end of ADM phases. But in Part IV, chapter 35, Architectural Artifacts remained.
• The Phase E and F descriptions have been reworked to match the level of detail in other ADM phases.
• The uses of terminology for Transition Architecture / Roadmap / Implementation Strategy have been clarified and made consistent.
• The description of Architecture Principles now divides into two types only - Enterprise and Architecture - whereas before they called out IT Principles separately. IT principles are now seen as just part of Enterprise Architecture.
• Corrections have been made to metamodel diagrams and applied to aspects of the metamodel.
• The terms artifacts versus viewpoint have been clarified and made consistent.
• Some of the artifacts have been renamed to better reflect usage:
• System/Data matrix becomes Application/Data matrix 
• Class diagram has been replaced with Conceptual Data diagram and Logical Data diagram 
• System/Organization matrix becomes Application/Organization matrix
• Role/System matrix becomes Role/Application matrix 
• System/Function matrix becomes Application/Function matrix
• Process/System Realization diagram becomes Process/Application Realization diagram 
• System Use-Case diagram becomes Application Use-Case diagram 
• System/Technology matrix becomes Application/Technology matrix 
• The relationship of the Enterprise Repository to the Architecture Repository is clarified in Part V, Chapter 41

For more information about changes I recommend to read whole official document written by Open Group.

http://pubs.opengroup.org/architecture/togaf9-doc/arch/chap04.html