Barry Kooij has released a new plugin, called WordPress Notification Manager. I credit myself and my complaining almost completely for this getting done. Thanks Barry.
WordPress Notification Manager takes those frustrating WordPress notifications and groups them in a toolbar dropdown — a big win!
It could have some issues with custom notification implementations, so it’d be great for us to all test it and see how we can break it. If the plugin is well adopted, I think it could make for a nice proposal for WordPress core.
Now just look at how pissed this cat is about traditional WordPress notifications: