There was a debate three years ago, there was always a debate between the two but it is true that a 30 something Ronaldo with his consistent performance and deliveries in the CL knock-out games have swung many people's minds into his column in the last several years.
One thing though, I have seen Messi getting compared with Maradona often and a few times to Pele even (not often), but I have never seen Ronaldo getting compared with those two. I think there is no denying when it comes to scoring goals Ronaldo is one of the top of the top, up there with the likes of Gerd Mueller etc. But overall as a footballer and his impact to the game he is not there with the likes of Pele/Maradona and Messi.