It was such a phenomenal question and what I wanted to do for so long just to add some scripts added in Byobu-5.73 and released a new function :-)
Starting with this version of Byobu, you can now use Shift - F9 to enter a command and send to all panels (splits) or Ctrl - F9 to enter a command and send a window to everyone.
Here you can see the demo: http://blog.dustinkirkland.com/2014/09/apply-updates-to-multiple-systems.html
This feature is available in Ubuntu 14.04 LTS (trusty), or you can always install the latest version from ppa: byobu / ppa or build / install from the source.
Full disclosure: I am the author and accompanying Byobu .
Dustin kirkland
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