I tried wakesurfing behind my I/O. I didn't have the weight right though so I couldn't let go of the handle. I was originally going to make some kind of floating platform to protect me from the "evil propeller" but it wasn't necessary. I can't really see getting that close.
My home-made hydrofoil stabilizer thingy helps with the safety though. It rides a couple inches under the water, projects all around the prop and would make it EXTREMELY difficult to touch it with your hand or whatever...I don't know if you could do it if you tried. It might have been a little scarier without the plate though.
Here's a pic: