ikegami,
Well, it was intended as an unspoken excersise for the reader/EchoAngel. By using a lexical FD, I thought it would be possible to make the magic work for only certain parts of the code and that when it fell out of scope Perl would DWIM and revert back to STDOUT.

As I was replying to this node I thought I better check it - turns out that it doesn't do what I thought it would. Subsequent prints to a lexical file handle that was selected but has gone out of scope still goes to that filehandle instead of reverting back to STDOUT. In light of this new discovery, the dup of STDOUT is not necessary, but it still had value - I learned something cool.