I'm really hoping that Masto's federation can give us the oldschool niche-community pseodoanonymity/obscurity that the last decade of internet development and centralization has slowly displaced.
I came in on the tail end of the era of finding a cool forum full of interesting people and be able to post there technically publicly but without much risk of being discovered by "the public".
IRC was (is?) the last truly great distributed platform. I'm hoping Mastodon can achieve what it did.