I'd like to be able to quickly glance over all the content updates on my apps. For example, if I'm coding in one virtual desktop, and different friends would send me messages via IRC, and Skype. A widget should notice that there's certain kind of updates available, and I would be able to pull those updates to the current virtual desktop as a preview window. Just by pressing one key I could go through all the updates and quickly interact with them.
I think this would lead to some kind of efficiency improvements, and could be quite neat. Here's the idea in a bit more detailed way: http://personal.inet.fi/koti/egaga/ideas/desktop.html