[$] What happens to kernel staging-tree code

The staging tree was and exFAT filesystems have reignited many of the
arguments over whether the staging tree is beneficial to the kernel
community or not. LWN cannot
answer that question, but we can look into what has transpired in the
staging tree in its first eleven years to see if there are any conclusions
to be drawn there.
A lot of code has gone into the staging tree over the years; what happened
to it thereafter?