With the redemption, G-d will "pour his spirit upon all flesh" - everyone, without exception, will be granted a spirit of prophecy.
In the book of Joel (3:1-2) there is a prophecy that with the redemption, "I will pour my spirit upon all flesh; your sons and daughters will prophesy; your elders will dream dreams, your youths will perceive visions, and in those days I will even pour my spirit upon the servants and maidservants."
This verse in Joel has a dual connotation: On the one hand, G-d informs us that with the redemption He will "pour his spirit upon all flesh" - everyone, without exception, will be granted a spirit of prophecy. At the same time, not everyone will prophesy on the same level. Some will be actual prophets, others will "perceive visions," and others will simply have the spirit "poured" upon them.
According to tradition of our sages, the prophets of old used to wear a distinctive garment to indicate their status. The Lubavitcher Rebbe raises a question: If, in the time of redemption, everyone will merit the spirit of prophecy, will anyone wear this distinctive garment? The Rebbe postulates that since there will be various levels of prophecy, those who are on the highest level will wear the special garments, so that those who wish to clarify various points of their prophecy will know whom to consult.
To note the words of Maimonides, at the very end of exile the spirit of prophecy will return, as a preparation for the coming of Moshiach. Prophecy will rest on certain select individuals. The Lubavitcher Rebbe, said that in our generation, the final generation of exile - has already merited this. His announcement about the imminent arrival of Moshiach was pronounced in a spirit of prophecy.