I would like to see somthing in the admin panel where it says that a update is available. Maby somthing like a bar that drops down at the top of the page or some text in the free space on the left had side of the admin area.
Yes, but there aren't that many people that will actually check their emails.
I think something really small, that gets data from this site and displays it on the AdminCP as most people who own an image website would check it at least every day or second day.
I'm sure it's not hard to implement, it would't put that much extra strain on cheveretos server, as it's would only would check the current version.
Unless I explicitly say "this will be in the next release" don't expect any date. For instance, version 3.2 with responsive theme could be available next week. But don't ask me for multiservers or something like that because I have no idea.