I think the Steelers did as good a job as they could with the offensive line - they even acted quickly when they saw DeCastro would not be ready for the season. As far as the guys reaching their potential - alot hinges on health and coaching - and it seems the coaching will be an improvement and as far as health - its a young group so that's works in our favor also.
Honestly more worried about ben's arm than the o-line - that seems to be the biggest X factor for the offense.