I think we could use a notication system in sublime, or at least the API to be able to put one together. We have the new HTML based popup system which works great, and I think we could build on that to provide a way to display popup panels that are independent of cursor position.
I have included a screen shot of a very basic mockup of such a system, although I would have to think about keyboard focused users with dismissing the notification.
I think this would serve the need for a notification with higher visibility than flashing a message in the status bar, but less obtrusive than displaying a message dialog.
What I had envisioned is something similar to the popup API where you could supply html define location within a window or possibly even define a view if the notification is related to a specific view.
Package control could use this functionality to display a list of packages with updates available when the user disabled automatic updates.
I am sure there are other use cases for such a system. Below is a screen shot I’ve created to show what I had envisioned.