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.
ScottK might have something to say ... 
I wish to see it (global menu) integrated with current app control plasmoid.
Man, it would rock. App icon as menu button – compact, clean and functional.
We’ve discussed that idea with upstream.
It seems (so far) more logical to put the menu on the left and the appcontrol on the right since that’s more like where these items usually go when they aren’t embedded in the panel. This would require some change in the appcontrol widget to look logical (that isn’t done yet), perhaps presenting the app icon as menu button in the menubar.
I expect we’ll experiment with this a bit before it gets upstream.
For me, it would be the most logical to put (separate) app icon with menu on the left side of panel and window control buttons (maximize, close) on the right.
What’s currently done – menu on left, app control on the right, it logical only partly for me. I always had (as lazy person) title of window on the left.
Well, it’s complicated, but going right way 😉 .