I think it would be an hugely helpful feature to be able to input notes and rhythms via voice command. A comprehensive general voice command feature could help blind or disabled folks use the program, but even a partial/more limited basic voice command feature could be extremely useful for those with mild hand/wrist/forearm pain from computer use.
An comprehensive voice command feature would allow you to do almost everything via voice command- "File menu" (would drop down on screen) "new document with wizard setup" (setup dialogue box would open) and one could navigate with voice commands. Once opened, entering notes might sound like "simple entry", "8th note", "G, B, Bb" "16th note", "E", etc.
More simply, there could be a voice command note entry only feature - the layout and more complicated operations would be done normally with clicking/keyboard shortcuts, and "voice entry" would be an option alongside "simple entry" and "speedy entry", etc.
I'm currently using the ancient 2007 version on mac OSX 10.4.11.