We rolled over today!!! Well, kind-of. We were doing tummy time, and I had Steven propped up on his arms a bit, and as I was watching, he rolled right over to his back. The look on his face was hilarious--wide eyed, like "what just happened??"
I put him back on his belly, again propped up a bit on his arms, and he started trying to roll over again. It didn't happen, but that's probably partly due to our limited tolerance of tummy time. He got out of it later on by spitting up all over his play mat. That is now in the wash, and he gets a brief break. We still have the boppy though :)