Re: What happened to the "Commodore" Rank?
FWIW, Memory Alpha says that insignia is for a Chief Petty Officer: http://en.memory-alpha.org/wiki/File:Cage_chief.png
And they idenitify that fellow in the picture as CPO Garison: http://en.memory-alpha.org/wiki/Garison
USS Galileo Galilei, NCC-8888
Starbase 31, Daran V
Prima Inter Pares