A great thing I love about Ubuntu running the latest version of Unity is the ability of the HUD. It is the most powerful tool I choose to use on my PC when doing major photo editing on Gimp or video clipping using OpenShot. I hate having to manually look through all the menus in an application when I need my work done as soon as possible, and HUD makes finishing that work as quickly as possible a reality, something only available in Unity, not even Windows 8 or Mac OS X have any tool just as powerful and precise.
But, there are problems with Unity in which I don't like, such as instability issues, and a cluttered desktop experience. I love the Gnome desktop just for that reason: My desktop space is free, but it's still customizable and easy to use and navigate through.
What my perfect desktop user interface would be is essentially Gnome 3.10, but with a Unity-like HUD feature that I can easily find what I need in my application menus without manual digging.
Can we make this happen?
*The functionality would be useful for all applications. Applications ranging from a simple calendar to a more complex app like Gimp would take advantage of this useful feature, much just like in Unity.
*It can be useful for applications without menu bars, as long as the developers add those background commands and services that will allow HUD.
*As for context menus and selections? Unity does it, why can't Gnome? As in, why not, with the press of the Alt key have a universal command search menu pop up in-shell? It wouldn't be preferred on a by-app basis, because each developer may not make the HUD features present or may not make the HUD even look the same, thus leading to an inconsistent UI for the HUD feature. It will blend in with the Gnome UI unanimously, and maybe the Gnome Devs can find a way to make it specifically unique to Gnome, design-wise.
* Independent from whether we want this or not: it is impossible for us to implement this for all applications. We could support it for applications that use the new GMenu API (most applications only use it for the app menu so far, they would need to port their "normal" menubar as well) which is only available in GTK+-3. The downstream patches Canonical applied to GTK+-2/GTK+-3 to support the HUD without explicit support from applications are terrible hacks that are not acceptable upstream. And then there are applications that don't use any version of GTK+ (Firefox, LibreOffice, everything using Qt, ...) which are completely outside of our control, so no HUD for those as well. -- FlorianMuellner