The follower won’t be blocked and can follow again in the future.
UPDATE 10/12: After a month of testing, Twitter announced yesterday that this feature is now available to all web users, allowing you to quietly remove followers while avoiding the backlash blocking people can trigger. Original Story 9/8: As with all social networks, some Twitter users suffer abuse from their followers. Blocking is one way of removing that abuse from your timeline, but it’s not a quiet way of silencing detractors. With that in mind, Twitter is experimenting with a new way to get rid of unwanted followers without them knowing about it.
