As for getting rid of managers, that won't happen - and nor should it. In a lot of places there is management when there shouldn't be, but when you're working as part of a larger organization - say, more than ten people and/or three "departments" - good management (by someone dedicated to that role) is essential for success.
Yes I do and I know a case with a document management system created by one developer and one analyst, which is now used by the Government of one country, including ministries and the PM's office. The competing offers for the same Govt were from a few superhuge and well known software corporations, but they all lost it to that application.
but when you're working as part of a larger organization - say, more than ten people and/or three "departments" - good management (by someone dedicated to that role) is essential for success
Actually no. Producing self-contained, self-sufficient software component has, in principle, very little to do with the size of the organization that creates such components. Small departments can be under the same financial roof, but functionally such small groups will become more and more independent in the future I think.
What we think of programming will evolve into using incredible high level scripting languages and frameworks. Programs will be very short.