Today was my second lesson, and I managed to stand up for most of the time. Aside from when I saw a huge school of fish, got distracted., stopped concentrating for a moment and fell off the paddleboard. I barely had time to say, "Ooh fishies" before I hit the water.
In a few short days I have gone from being shit scared of the waves to thoroughly enjoying my time in the water.
As far as fitness goes, I aint no Guru, but I would say it is pretty good for you the way it gives you an all over workout (especially the thighs). That may explain why it is becoming a hugely popular sport.