133 thousands blocks occupied 480 MB. What will in future? Gigabytes?
Is about 60 thousands bitcoin users, not all are all time online, but miners are.
All of users keep all blocks.
Some redundancy is needed for example even square root of users: each user keep only random blocks 1/250 of whole, is system database is still 250 redundant, user can keep digest block(group of blocks), could be all blocks on one server with blockexplorer but main idea is distributed database