Paul clearly taught in 1 Cor. 14 that all should seek the gift of prophecy. For example:
1 Follow after charity, and desire spiritual gifts, but rather that ye may prophesy.
24 But if all prophesy, and there come in one that believeth not, or one unlearned, he is convinced of all, he is judged of all:
31 For ye may all prophesy one by one, that all may learn, and all may be comforted.
Christ taught that everyone is to be considered our neighbor.
It appears that the concept of being the watchman on the tower, an assignment given in times of old to those who could prophesy, is as relevant today as we are all invited to become prophets. Although @Rick's answer shouldn't be ignored — there will always be many who claim to be prophets, using the obligation to be a watchman to further one's own desires rather than the glory of God. True watchmen will consistently follow Christ and seek after the well being of others, even to the exclusion of their own wants.
I am not Catholic, but I would be hard pressed to review the life of someone like Mother Teresa and not accept her devotion as one of the Lord's watchmen.