I always provide an outline for a number of reasons.
First, it helps participants scan the slide handouts in the same way as an index.
Second, it helps align expectations with the audience, so they have the chance to leave for lunch if they don't like what they see.
Third, it helps set a "learning frame of reference". The structure of your presentation most likely reflects how you mentally structure the topics you are going to present - use that to give the audience an initial high level bird-eye view of what is going to happen. A good idea is to not only have headline such as "Personas", but maybe also have a subtitle to infer some meaning: "Personas - getting to know your users", for example.
Finally, I learned that you should always provide a brief outline when presenting at an oral exam. Quite often you are asked a question that are not entirely in context with what you are presenting at the moment and by referring to your outline, you can tell that you will get back to that question in detail once you get to the corresponding part of your presentation. This helps you keep your presentation on track and applies to a lot of other situations than exams.