Mark Shuttleworth already announced the Global Menu for Ubuntu Netbook Edition, 10.10. The idea to minimize usage of vertical space is also a key design principle behind Plasma Netbook. Fortunately, Aurélien Gâteau, part of Canonical’s Ayatana Project, has provided a Qt/KDE implementation (for those interested in such details, the related Qt patches will go upstream in Qt 4.8).
If you want to experiment with this yourself on Maverick, you just have to install plasma-widget-menubar and then add the widget to your panel. Once you restart your session, it should be working. You can right click on the widget to configure it. Aurélien loves bug reports, so give it a try and keep him busy.
We would like to include this in the default Kubuntu netbook interface for Maverick, 10.10 if it’s mature enough. It has a few rough edges yet, but it’s already advanced significantly from the prototype demo we saw at UDS.