Rogue Amoeba: The Developer News Window.

'''As our user base has grown over the years, the ability to handle problems rapidly has become increasingly important for us. Even a brief service outage or rare bug can cause hundreds of emails to come flooding in. While we have a large user base, our team is still small, so heading off problems with fast updates and useful communication is essential.'''

I think this is a great idea and I plan on adding something very similar to VoodooPad and Acorn in the future. I actually added something like this to VoodooPad 4.3.6 to let people know about the version 5 update (though not quite as sophisticated). But I love what Rogue Amoeba did and I'll have to take some of these ideas and bundle them into a new implementation.