It could be useful. In the past I have used Opera's built-in voice engine and it worked great.
If you think about naturally sounding voices it would be nice to add language selection.
Simple plugin that shows you how to create a settings page in the ACP. Use this to bootstrap the next plugin you write!
Install via NPM:
npm install nodebb-plugin-admin-sample
You'll need the latest bleeding-edge version of NodeBB (0.0.8 or later) for this plugin to work.
Can you add a bit to the plugins documentation on the wiki to help other users figure out how to get admin routes into their plugins?