It will be just one variable among many moving pieces related to how the bench comes together and, more important, where Doumit is most valuable in the long term.
Cool. One question: will Paulino also have to prove himself defensively to prove he's viable as a starter? Because if Ryan Doumit has to prove he can play defense, it seems only fair that Paulino should have to also. The 129 games he played last year didn't resolve the issue at all.
Snark aside, though, the Pirates' openness to using Doumit at catcher in more than an emergency role could enable lots of things to happen, all of them good. Doumit could play more, Paulino could play less, no-hit backup catchers (Michel Hernandez, Carlos Maldonado, Raul Chavez) could play not at all, and a credible major-league hitter like Doug Mientkiewicz could grab the last bench spot. I'd love to see a full-fledged position battle evolve here; hopefully Doumit can stay healthy long enough for that to happen.