Yes, there's a big risk of getting motion sickness. Beware.
But when you start playing you might even get to like it. I won't say i enjoy it, but i have no problems playing shooters on my ps3. I mean FPS with that, there never was any problem with 3rd person games which i think are best played with a controller anyway. Whatever genre. And i even enjoy playin the new XCOM on console, even if i can't turn off the camera that always zooms in in action.