Thanks ScottyS,
I am a speaker so I do a lot of presenting. I must admit I have been using the Surface Pro 3 during presentations in the same way as my old laptop. Just to show the PowerPoints. I usually do have a bluetooth mouse with it and a small presentation clicker to advance the slides.
The idea of marking up and highlighting PowerPoint slides is very intriguing as is the thought of using OneNote like a whiteboard.
I ordered new batteries for my Surface Pen yesterday. Hopefully they show up soon so I can try out some of these ideas.