Didn't experience any nausea watching Safari in the Okavango on my 58" 3D Panasonic. For me, it's my favorite of the 3D demo videos (of which there are far too few). The complaint I have is having to pay five bucks each for a couple of short underwater 3D videos (I have them recorded but they'll just sit on the DVR unwatched until the ripoff price is either removed or drastically reduced).
Sure enjoyed watching the world cup in 3D. I hope ESPN continues on with ever more 3D sports.